Tentacle Pillar

Based on game build 714014 | Last updated: 2026-03-07

Overview

tentacle_pillar implements the main boss entity for the Marsh Tentacle encounter. It coordinates arm spawning, health states, teleporter synchronization with its linked hole, and transformation to/from a retracted hole state. It uses the health, combat, playerprox, lootdropper, and teleporter components, and includes custom logic for emergent behaviors, player-triggered attacks, and world-state changes via map tile and set piece handling (especially for the tentacle_pillar_atrium variant).

Usage example

This entity is spawned automatically during world generation and not directly instantiated by mods. However, a modder may reference or extend its behavior:

-- Example: spawning a tentacle pillar programmatically (advanced use only)
local pillar = SpawnPrefab("tentacle_pillar")
pillar.Transform:SetPosition(x, 0, z)

-- Example: triggering emergence programmatically
pillar.components.health:SetMaxHealth(TUNING.TENTACLE_PILLAR_HEALTH)
pillar:OnEmerge()

-- Example: overtaking to switch to hole mode
local hole = pillar:Overtake()

Dependencies & tags

Components used: health, playerprox, lootdropper, combat, inspectable, teleporter, hauntable (via AddHauntableCustomReaction), and burnable/fueled (via loot logic, not directly added here but referenced by lootdropper). Tags added: cavedweller, tentacle_pillar, wet, NPCcanaggro. Tags checked: notarget, player, burnt, structure, hive, monster, animal, creaturecorpse, debuffed, hiding, INLIMBO, irreplaceable, event_trigger.

Properties

Property	Type	Default Value	Description
numArms	number	0	Count of active tentacle arms currently spawned.
arms	table	{}	Map of active tentacle_pillar_arm entities (as keys).
overtaken	boolean or nil	nil	True if this pillar was overtaken (e.g., by a player teleporter action).
overtakenhole	entity or nil	nil	Reference to the hole prefab spawned during overtaken retraction.
spawnLocal	boolean or nil	nil	Flag set when spawning arms locally (e.g., after a player attack).
overtaken in linked hole	boolean	nil	Indicates whether the linked tentacle_pillar_hole is in an overtaken state.
_tpqueue	table or nil	nil	Queue of pending teleporter activations during overtaken state transition.

Main functions

OnEmerge(inst)

• Description: Triggers the boss’s emergence from the ground. Makes the entity invincible, plays an animation and sound, shakes cameras, adds notarget tag, and schedules a callback when the animation completes to remove invincibility and tag.
• Parameters: inst (entity) — the tentacle pillar instance.
• Returns: Nothing.
• Error states: Has no effect if the entity is already dead (IsDead()).

OnDeath(inst)

• Description: Handles the boss’s death sequence: retracts all arms, drops loot if not overtaken, and transforms the pillar into its linked hole (unless overtaken, in which case it retracts the linked pillar/hole too). Plays death animation/sound and schedules SwapToHole.
• Parameters: inst (entity) — the tentacle pillar instance.
• Returns: Nothing.
• Error states: If inst.overtaken is true, skips loot and omits linking logic.

Overtake(inst)

• Description: Forces immediate retraction of the pillar and transforms it into a tentacle_pillar_hole while preserving teleporter links. Prevents entry while overtaken.
• Parameters: inst (entity) — the tentacle pillar instance.
• Returns: inst.overtakenhole (entity) — the newly created hole or existing one, if any.
• Error states: May return nil if no hole has been created yet.

SwapToHole(inst)

• Description: Transforms the pillar entity into a tentacle_pillar_hole, preserves or nullifies teleporter links, and applies overtaken flags appropriately.
• Parameters: inst (entity) — the tentacle pillar instance.
• Returns: Nothing.
• Error states: Linked pillars/holes must match expected prefabs; otherwise, state may be inconsistent.

SpawnArms(inst, attacker)

• Description: Spawns up to TUNING.TENTACLE_PILLAR_ARMS tentacle arms around the pillar in a circular layout. If attacker is provided, shifts spawning toward the attacker. Calls KillArms first if arm cap is exceeded.
• Parameters: inst (entity) — the pillar instance; attacker (entity or nil) — optional entity that triggered spawning.
• Returns: Nothing.
• Error states: Returns early if arm cap (TUNING.TENTACLE_PILLAR_ARMS_TOTAL) is reached.

DoRetract(inst, overtake)

• Description: Immediately kills the pillar, sets overtaken flag, and removes invincibility.
• Parameters: inst (entity); overtake (boolean) — whether this retraction is due to an overtaken teleport.
• Returns: Nothing.
• Error states: Has no effect if already dead.

OnActivateByOvertake(inst, source, doer)

• Description: Queues teleporter activations that occurred while the pillar was overtaken (i.e., switching to hole mid-activation).
• Parameters: inst (entity); source (entity); doer (entity).
• Returns: Nothing. Appends { t, doer, source } to inst._tpqueue if present.

OnLoadPostPass(inst)

• Description: Called after loading to resolve link state with the paired teleporter. Ensures overtaken pillars/holes are correctly retracted or enabled based on overtaken flags.
• Parameters: inst (entity) — the pillar or hole instance.
• Returns: Nothing.

Events & listeners

• Listens to:
  • death (OnDeath)
  • onremove, death (via inst.arms[arm] tracking; calls _onstoptrackingarm)
  • animover (OnEmergeOver, then later SwapToHole)
  • entitysleep (SwapToHole)
• Pushes: None directly (only delegates via event callbacks and component behavior).