MJStalker

Adds two Michael Jacksons to Lethal Company as inside enemies: ST, the stalker in the Billie Jean outfit, and SC, the Smooth Criminal thief in the white suit. Everything is inside the one dll (the body is generated by the plugin, the head and the dance are converted from supplied files and embedded), so there is no asset bundle and no other mod is required.

Everyone in the lobby needs the mod, and the same version of it.

What he does

Phase	Behaviour
Roaming	Wanders the facility. Every so often an ad-lib echoes down the halls. When he sees a player he starts stalking them.
Stalking	Sneaks along the route to his target and stops just short of where the target could see him, then leans out around that corner to watch. He can notice and watch players from up to 70 m away.
Spotted	If a player within 30 m keeps looking fairly directly at him for a full second, he yelps (fear spike for whoever saw it) and moonwalks away from the players for 10 seconds, then goes back to roaming. A glance is not enough, and each player has to hold the look on their own. He only has the nerve for this three times: after that, spotting him (or hitting him) starts the chase on whoever did it.
Chase	If he watches players from within 30 m and nobody looks at him for 8 seconds, the music starts - from the very first time he stalks you, and with any number of players there. He goes for whichever player has their back most turned to him. For the first 5 seconds he dances on the spot and that player cannot move or look away from him. Then he comes after them, slowly at first and getting faster the whole time: half walking speed at 5 s, walking speed at 10 s, just under sprinting speed at 25 s, and faster than you can sprint from 35 s. He keeps coming until he has lost sight of you for 12 seconds; each later chase adds another 12 (24, 36, ...). It also ends if you die or leave the building.
Caught	If he touches you during a chase you are sent to the stage (see below). He stays in the facility and goes back to roaming.

He is as common as the Bracken: on each moon his spawn weight is copied from the Bracken's weight there (rare on the starter moons, common on Vow, March, Rend and Titan), along with the Bracken's time-of-day pattern. FollowEnemy, FollowMultiplier and FallbackRarity under [Spawning] change that; the log lists his weight and share on every moon when a lobby starts. Only one of him is alive at a time.

Catching him makes him more dangerous: the 8 seconds drops by 2 every further time he is caught stalking (8, 6, 4, then 2, where it stays).

His eyes shine white in the dark while he is stalking.

He dies after 10 hits (a shovel swing is one hit). Hitting him while he roams or stalks also counts as catching him, so he yelps and moonwalks off - or, once his nerve is gone, comes for whoever hit him. He can be stunned.

The chase dance is converted from an MMD motion (.vmd) and is built into the plugin: 127 seconds long, looping. Each chase starts 6.5 seconds in, where the slow zombie shuffle ends and the choreography begins (DanceStartOffset). The dance follows the chase music's clock, so if your music file is the track that motion was made for, set MusicStartOffset to the same 6.5 (or DanceStartOffset to 0) and the two stay in step.

The Smooth Criminal (SC)

Same body and head as ST, in the Smooth Criminal outfit: white pinstripe suit, blue shirt, white tie, blue armband, white fedora with a black band, white spats.

Phase	Behaviour
Wandering	Walks the halls looking for anyone carrying something.
Chasing	Goes after the first player he sees with an item (faster than you walk, slower than you sprint; heavy loot slows you down). He gives up after 8 seconds without seeing you. Dropping your things does not shake him off.
Stealing	When he reaches you he hits you (20 damage) and takes one random item from your inventory - any slot, the off-hand slot included. If you dropped your things while running, he takes one of those instead, straight off the floor.
Dancing	He holds it up and dances for as long as his voice line lasts, then vanishes in a puff of smoke with a spin kick: anyone within about 2.5 m takes 25 damage and is knocked back.
Gone	Two seconds later he turns up somewhere far from everyone in the facility and starts again.
Ship raid	Each time he vanishes (and about once a minute while wandering) there is a 25% chance he turns up in the ship instead, takes something lying there, dances, says his line and vanishes back into the facility.

Hitting him makes him vanish at once - no dance, no line. If he was dancing with something he just took, he drops it.
But he remembers who hit him. About 12 seconds later he turns up out of sight 15-38 m from you and hunts you down - he does not give up when he loses sight of you. When he catches you it is a 45 damage kick that knocks you back, and he still takes something. Hitting him again starts it all over.
He finishes off the wounded. None of his hits kill a healthy player outright, but a hit that takes your last health, or would leave you critically injured (under 10 HP), is fatal: it sends you to his own stage show (below). At full health, the fifth theft is the one that does it. (FinishLowHealth in the config turns the under-10 rule off; the game's usual "spared at 5 HP" never applies to him.)
Stunning him (stun grenade, zap gun) stops him vanishing when hit, so you can beat him while he is dazed.
He has 4 health, so he survives three shovel hits. His health carries over between appearances.
Killing him drops everything he has stolen where he falls. Anything he still has when the ship leaves is gone.
He uses the same spawn weights as ST (both follow the Bracken). Only one of each is alive at a time.

The stage show

When he catches you, your screen goes to a concert stage where he performs a full number: the supplied song, dance, camera work and stage. Press SPACE to end is shown at the bottom right; pressing it (or the song finishing, about five minutes) ends the performance and you die there and then, into the normal death spectating. Pressing SPACE in the first two seconds is ignored, since you were probably mashing it.

While you watch:

you have not died yet. To everyone else you simply vanish from where he caught you, your items drop to the floor, and your body appears there when your show ends;
nothing in the facility can target you, and you cannot move or do anything;
you hear only the song, not the facility;
he is still on the map hunting the others. If the round ends first, the show ends with it.

With Debug Keys turned on (see Testing), press F9 while landed on a moon to try it without being caught (it counts as being caught, so you die when it ends).

The show's settings are under [Stage Show] in the config: on/off, song volume, how far into the performance it starts, the size of the stage next to him, whether a body is left, and how brightly he is lit. With it off he kills on contact as before.

The Smooth Criminal's show

When one of the Smooth Criminal's hits would kill you (a steal, a revenge kick or the spin kick), you are sent to his show instead of dying on the spot. It works exactly like ST's: your screen goes to the stage, Press SPACE to end is shown at the bottom right, and you die when you press it or the song ends (about 4 3/4 minutes). He still takes the item, and he is still on the map.

The song is Smooth Criminal, on a big arena stage with truss arches and rows of ball lamps that pulse on the beat. The big LED wall behind the stage and the two screens either side of it show the live picture: whatever the show's camera is filming.
The curtain: the show opens on a closed white curtain lit from behind. His shadow dances on it; when the band comes in the four dancers' smaller shadows join him. The shadows are thrown by the actual models in their actual poses (his suit and fedora, the crew's suits, helmets and gray hats), redrawn 30 times a second on a background thread. Then the curtain rises from the middle and the line is revealed.
The lights change colour with each part of the song (blue, pink, green, white, amber, red, cyan, magenta), with a coloured pool of light under each performer.
He dances in the white suit, with four backup dancers: the crew's own player model in the default orange suit, each in a gray fedora. Near the end a Bracken walks on from the wings, throws the dynamite that goes off beside the stage, and walks off again. The crowd waves glow sticks in the stands.
The dancers and the Bracken are the game's own models, borrowed when the show is first built; the plugin finds their arms, legs, spine and head by shape and puts the dance on them. If that ever fails, the show goes on without them (the log says why: look for lines starting Stage copy of).
The camera follows the reference performance shot for shot: the static wide on the curtain, the push-in as it rises, the shots from behind the line, the side angles, the close-ups, the reverse shot into the crowd at the explosion, the high angle over the fallen dancers and the wide from the back of the hall at the end.

With Debug Keys turned on (see Testing), press F10 while landed on a moon to try it (it counts as a killing hit, so you die when it ends). Settings are under [Smooth Criminal Show]: on/off, song volume, where it starts, song offset, the backup dancers and the Bracken on/off, how brightly they are lit, and the hat size.

Sounds

Included, in the folders next to the plugin:

sounds/roam/ - 42 ad-libs. One plays at random every so often while he roams, and one when he is caught peeking.
sounds/thriller/ - the chase music (loops for as long as the chase lasts).
sounds/show/ - the song for the stage show. The dance and camera are timed to this recording (the music starts 7 seconds in); if you swap it, SongOffset shifts it against them.
sounds/steal/ - the Smooth Criminal's line after a theft. He dances for exactly as long as it lasts.
sounds/scshow/ - the song for the Smooth Criminal's show. The dance, lights and camera are timed to this recording; if you swap it, SongOffset under [Smooth Criminal Show] shifts it against them.
sounds/spotted/ - empty. Put clips here only if you want different ones for being caught.

To change them, swap the files (.ogg, .wav or .mp3). In r2modman: Settings -> Browse profile folder -> BepInEx/plugins/...MJStalker/MJStalker/sounds. Files are also picked up from BepInEx/config/MJStalker/ (same folder names), which survives reinstalling the mod.

Testing

The testing keys are off by default. To use them, set Debug Keys = true under [Debug] in the config (each key can also be changed or set to None there).

Host only: land on a moon and press F8 to spawn him inside the facility (near you if you are already inside).

Host only: F7 spawns the Smooth Criminal the same way.

Anyone: F9 while landed sends you to the stage show.

Anyone: F10 while landed sends you to the Smooth Criminal's show.

Config

BepInEx/config/MJStalker.cfg is created on first launch: which monster's rarity he copies, speeds, the 8 / 10 / 12 second timers, how directly you must look at him, contact damage, his health, eye glow strength, volumes, where the dance and music start, the stage show, the Smooth Criminal ([Smooth Criminal]: on/off, health, speeds, sight range, ship raid chance, vanish time, all his damage numbers, the spin kick's reach and how soon he comes back for revenge), his show ([Smooth Criminal Show]), and the debug keys. The host's values control his behaviour; the stage show settings are each player's own.

Credits

Stage: "MMD Live Stage Club 2.0" by Philippe-n-12 (https://www.deviantart.com/philippe-n-12), converted for use here.
Stage dance, camera motion and song: the supplied Billie Jean MMD files (camera file credited to Crows).
Smooth Criminal dance: the supplied smcr_1.vmd MMD motion.
Smooth Criminal show: dance motions for Michael, the four backup dancers and the walk-on, and the gray backup-dancer hat, by bun_ftd (Smooth Criminal MMD motion pack), converted for use here. The author's terms do not allow the data to be reposted or redistributed, modified or not - ask them before sharing this mod publicly.
Arena and stage: "アリーナ" by ろっし/ビリヤードP, CC BY-NC 3.0 (https://creativecommons.org/licenses/by-nc/3.0/). Changed for this mod: rescaled, turned round, the front of the stage extended, the name over the screen replaced, the side logo panels and the screen net left out, the screens showing the live picture, the seats left out (their layout is reused for the crowd's glow sticks). Non-commercial use only.