I created this discussion to not keep editing that one comment of mine because it's bit annoying to try keep it sorted there.
Here will be general stuff, mimicry/abilities of Rot, Scavenger crafts, maybe some tips idk. Something that can be useful for others.
I will edit it from time to time when something needs to be changed. (Tell me if I missed something important)


To eat food/attach item to cyst —> bring it close to your body and press Throw. (Keep holding Grab while doing this)
To mimic/absorb item —> same as above but press Map instead of Throw. You need at least one additional cyst attached to your core to mimic item.
Unless you need precision it's always nice to hold Jump when moving some object.
Rot can grab creatures with movement tentacles to make moving it easier. (Extend your movement tentacles to some creatures and they will try to grab it)
Moving creature really far and releasing Grab makes tentacle go back to your core pretty fast, creating some nice velocity to work with.
Cysts affect your mobility, strength of tentacles, survivability, if creature will flee upon seeing you. (With enough cysts you'll be able to absorb alive creatures and other mobile Rot cysts)
You can deal damage to creature by striking it with another creature or your cyst.
Rot doesn't take fall damage.
You can detach additional cyst from The Rot by getting prehensile tentacle near it and pressing Grab. If detached cyst is alive you can attach it back same way as eating food. (If cyst is dead it will be absorbed for food instead)
After cyst's health goes in double negative (-2/1 in Mouse Drag) it will shatter. (Vulture Mask mimicry is exception)

Rot Mimicry:
Hold movement key and then also hold Special keybind (Def: C) to activate ability. (You can only activate ability with attached cyst but passive and on death effects trigger for both attached and detached cyst.)
Detached cyst will retain mimicry that it had before being detached.
Switch Cyst Loadout (Def: V) — switch between three different loadouts (abilities)
Clear Cyst Loadout (Def: B) — clear current loadout (return absorbed item)
Most abilities will destroy cyst after amount of uses: 6 for big cyst, 2 for small cyst.
(After • symbol goes passive ability of mimicry. Before is ability on activation)

Spear, Fire Spear — Closest to that direction cyst shoots needle that works like Spearmaster's one.
Explosive spear — First needle is explosive. •Cyst explodes on death if there's still explosives left. (Rot and its attached cysts won't take damage from this explosion.)
Electric Spear — Needles shock with electricity until absorbed spear runs out of charge. •Sometimes cyst creates electric charge that stuns creatures nearby on damage. (Will stun every creature nearby, including cysts not attached to Rot or Rot if this specific cyst is detached)
Bomb — Shoots cyst that explodes on impact. •Cyst explodes on death. (Rot and its attached cysts won't take damage from this explosion.)
Firebug Egg — Shoots cyst that sticks to terrain&creatures and explodes after ~8 seconds. •Cyst explodes on death. (Rot and its attached cysts won't take damage from this explosion.)
Vulture Mask (normal, king, scav king) — •Gives cysts armor that deflects spears and makes them more survivable. (But cyst will shatter soon after HP goes in negative)
Jellyfish, Tiny Centipede — Creates electric charge that stuns creatures nearby. (Doesn't destroy cyst on uses) •Sometimes cyst creates electric charge that stuns creatures nearby on damage. (Will stun every creature nearby, including cysts not attached to Rot or Rot if this specific cyst is detached)
Sporepuff — Shoots cyst that explodes with cloud of spores on impact. •Explodes with cloud of spores on death.
Lamp — •Cysts will glow with orange light if they're not dead.
Mushroom — Slows down time like mushroom. (Doesn't destroy cyst on uses)
White/Plain Pearl, Purple/Rot's Pearl — Shows list of absorbed creatures on the left (When pearl is overwritten by Rot). •Absorbed creature will be analyzed and data about it gets stored in this pearl's list. LttM can read this pearl. (Allows to do Pearl Quest)
Flashbang — Explodes one cyst like Flashbang. •Explodes like Flashbang on death.

You can mix these: (* means that order matters)
Spear, Fire spear * Bomb — Explosive Spear abilities.
Spear, Fire spear, Electric Spear + Jellyfish, Tiny Centipede — Visuals of electric spear, but spear isn't affected in any way (Jellyfish/Tiny Centpede will be wasted if you shoot needle). •Same as Jellyfish/Tiny Centpede.
Vulture Mask * Bomb — Same as Bomb. •Vulture Mask armor but doesn't explode on death.
Vulture Mask * Jellyfish, Tiny Centipede — Jellyfish/Tiny Centpede ability. •Same as Jellyfish/Tiny Centpede (But because of damage reduction it's harder to trigger).
Vulture Mask * Sporepuff — Sporepuff ability. •Vulture Mask armor but doesn't explode with spores on death.
Vulture Mask * Lamp — •Vulture Mask armor and Lantern glow.
Vulture Mask * Mushroom — Mushroom ability. •Vulture Mask armor.
Vulture Mask * Flashbang — Flashbang ability. •Vulture Mask armor + Flashbang explosion on death.
Vulture Mask * White Pearl — Pearl ability? (doesn't work rn). •Vulture Mask armor + Pearl passive ability.

Pearl Quest:
Rot has two endings with first being ascension and second being pearl quest.
To do pearl quest you have to fill every data slot in the list that appears when you use pearl ability. (To fill slot you need to absorb unique creature)
In total there is 26 slots. Top slot is only filled by one specific creature — Slugcat or Slugpup. (You get hint about what creature after filling all bottom slots)
Every creature has to be different, you can't fill two slots with Pink Lizard.
After filling every slot you will need to head in Outer Expanse and get to Journey's End part of it, when you get to last screen you'll get text asking to press Special keybind, then something interesting happens...

You can equip/unequip Vulture Mask and Wearable Armor Pieces by holding Grab.
Armor Piece can deflect one spear and shatters after. Vulture Mask deflects 3, King Vulture mask 4, Scavenger King Mask 7 spears before detaching (Those numbers regen overtime or reset if mask was detached by projectile).
By pressing Throw and then Jump in order you can do melee attack with weapon. This fuses held explosives even if it hit nothing.
Melee attack can deflect incoming projectile and/or fuse it early, just time it right.

Crafts
(Most crafts are same as Gourmands with these being unique)
Vulture Mask, King Vulture Mask + Spear — Mask with spikes
Vulture Mask, King Vulture Mask + Explosive Spear — Mask with spikes
Vulture Mask, King Vulture Mask + Electric Spear — Mask with spikes
Vulture Mask, King Vulture Mask + Fire Spear — Mask with spikes
Spear + Firecracker Plant — Explosive Spear
Spear + Tiny Centipede — Electric Spear
Rock + Spear — Armor Piece
Armor Piece + Firecracker Plant, Batnip, Popcorn Seed — Wearable Armor Piece
Spear + Firebug egg — Fire Spear

You cannot eat any food in parasite form.
You can grab creatures or item with your tentacle/leg? (While holding item you can't grab creatures. Throw to release held object)
If you grab creature and then keep holding Grab, you will take control of it. (Hold Special to leave creature)
Press Special to extend tentacle that can take control of creatures. (If you eat as that creature while it's controlled by tentacle you still get food)
Grab and Tentacle don't deal any damage to creatures.
Controled creatures controls are mostly same as in safari mode.
Lizards can jump and Grab items with jaw.
Controlled creatures eat with holding Grab near prey.

Artificial has mini-HUD that displays HP in left bar & amount of steam/jet left in right bar.
Grab+Throw — create stun explosion near you. (Deals damage to creatures)
Grab+Throw (with item in jaw) — launch that item.
Grab+Throw (when tongue hit creature) — explode creature connected to tongue.
Throw (midair) — hover midair for moment.
Using Grab+Throw (or just shooting tongue) too much will overheat Artificial. If you won't stop they will explode.
While in normal state you will start regenerating your HP after a bit. (Steam will appear)
White and Cyan lizards are afraid of you.

Doomed State:
After getting a lot of damage you will enter doomed state. (Exploding by overheating won't activate this)
Exclamation mark and another bar will appear above you. This bar is your last HP.
If you press any movement key this bar will start decreasing, same if you take any damage.
You can retreat (Backpedal) by holding Map, it doesn't decrease your HP.
This HP will regenerate if not interrupted. After it fully regens you enter normal state with steam regen.
If this last HP is gone — you're dead.