Tentacle Swarm

• Hydroid summons a creature from the deep, causing 4 / 6 / 8 / 10 tentacles to emerge from all surfaces within a marked location 3 / 3 / 5 / 5 meters in radius, cast over unrestricted range. Tentacles prioritize spawning beneath enemies inside the radius, with each tentacle capturing their initial targets or throwing them upward, dealing a maximum of 75 / 150 / 225 / 300 Magnetic damage upon emerging, on first contact with enemies, and when submerging as the ability expires after 10 / 13 / 18 / 20 seconds. Captured enemies are incapacitated in a ragdoll state and stay attached to the flailing tentacles; bypassing Shields 50 / 100 / 150 / 200 True Damage will be dealt per second.
  • Tentacle Magnetic damage and True damage per second are affected by Ability Strength, while number of active tentacles is not.
    • Magnetic damage calculation when accounting for Ability Strength is squared (e.g., with a maxed  Intensify, the tentacles will deal a maximum of 300 × 1.3^2 = 507 Magnetic damage at rank 3).
  • Magnetic damage is effective against Shielded and Proto Shields, but less effective against Alloy Armor.
  • Magnetic status effect reduces a target's current and maximum shields by 75% for 4 seconds.
  • Spawn radius is affected by Ability Range.
  • Duration is affected by Ability Duration.
  • Casting speed and charging speed are affected by  Natural Talent and  Speed Drift.
  • Tentacles detect and capture new enemy targets when they come into range.
  • Tentacles can capture multiple enemies at once.
  • Tentacles with captured enemies will flail their victims around slowly, allowing players to take aim and kill their targets.

• Tapping the button (default 4 ) casts the ability immediately. Holding the button for up to 2.5 seconds charges Tentacle Swarm, increasing the number of tentacles spawned up to 8 / 12 / 16 / 20 and spawn radius up to 300%, in exchange for up to double energy cost.
  • Tentacle Swarm's spawn area will be highlighted by Hydroid's energy color during the casting and charging animations.
  • Spawn area indicator visibly grows in size as Tentacle Swarm is charged.
  • While charging, an audible whale-like call from the Kraken plays.

• Can be cast while in Undertow liquid form to center Tentacle Swarm on the pool.
  • Quick cast causes all tentacles to spawn inside Undertow's radius, while charged cast extends the spawn radius outside of Undertow.
  • Tentacle Magnetic damage and True damage per second deal 200% damage when cast from Undertow, including tentacles that spawn outside Undertow.

• Casting Tentacle Swarm is a two-handed action that stops Hydroid's movement and other actions. Charging Tentacle Swarm is a two-handed upper body animation that allows player movement.
• Can be recast while active; however, only one instance of Tentacle Swarm can be active at a time. Recasting will replace the previous instance.
• Hydroid briefly summons the Kraken at the center of the spawn area as a visual effect. The Kraken emerges from a pool of water, then submerges slowly and disappears. Kraken is affected by Hydroid's chosen Warframe appearance and energy colors.
• Tentacles appear as translucent water tendrils emerging from a small puddle of water. Tentacles emit splashes of water periodically, as well as a steam particle effect at their base which is affected by Hydroid's chosen Warframe energy color.

Main article: Pilfering Swarm

Pilfering Swarm is a Hydroid Warframe Augment Mod that grants Tentacle Swarm a chance to yield additional loot from enemies killed while they're ensnared by the tentacles.

• Does not trigger Arcane Trickery enhancement.

• Animation is made and energy is wasted but no tentacles spawn