Engulf
As a standard action, the creature can move up to its speed, moving into or through the space of any creatures that are at least one size smaller than itself without penalty. Every creature in the engulfing creature’s path is automatically engulfed with no attack roll needed. A targeted creature can attempt a Reflex saving throw to avoid being engulfed; if it attempts this save, it can’t make an attack of opportunity against the engulfing creature due to that creature’s movement. On a successful save, the target is pushed back or aside (target’s choice) as the engulfing creature continues to move. An engulfed creature gains the pinned condition, takes the listed damage at the beginning of each turn it’s engulfed, is in danger of suffocating if it doesn’t have environmental protections, and is trapped within the engulfing creature’s body until it’s no longer pinned. An engulfed creature moves with the engulfing creature; this movement doesn’t provoke attacks of opportunity against the engulfed creature. A creature can engulf one creature that’s one size smaller than itself, up to two creatures that are two sizes smaller, or up to four creatures that are three sizes smaller.
Format: Offensive Abilities engulf (1d6+8 F, DC 13).
Source
Alien Archive 2 pg. 150