Hermit Crab SwarmCreature 4
Source Pathfinder Bestiary 3
Perception +11 (darkvision, tremorsense (imprecise) 15 feet)
Languages none
Skills Athletics +12
Str +4, Dex +2, Con +3, Int -4, Wis +1, Cha -1
AC 19; Fort +13; Reflex +10; Will +7;
HP 42
Speed 30 feet (swim 15 feet)
Immunities precision, swarm mind
Weaknesses Area Damage 5, Splash Damage 5
Resistances Piercing 5, Slashing 5
Darkvision
A monster with darkvision can see perfectly well in areas of darkness and dim light, though such vision is in black and white only. Some forms of magical darkness, such as a 4th-level Darkness spell, block normal darkvision. A monster with Greater Darkvision, however, can see through even these forms of magical darkness.
Tremorsense (Imprecise) 15 feetTremorsense allows a monster to feel the vibrations through a solid surface caused by movement. It is an imprecise sense with a limited range (listed in the ability). Tremorsense functions only if the monster is on the same surface as the subject, and only if the subject is moving along (or burrowing through) the surface.
Swarm MindThis monster doesn't have a single mind (typically because it's a swarm of smaller creatures), and is immune to mental effects that target only a specific number of creatures. It is still subject to mental effects that affect all creatures in an area.
Swarming Snips
Each enemy in the swarm's space takes 2d8 piercing damage (DC 20 basic reflex save).
Creatures that fail this save also take 1d4 Persistent Bleed Damage.
When hermit crabs find a shell that is too large, they lie in wait for others to arrive and move into the shell, abandoning a possible replacement. This can form a large chain of queuing crabs waiting to upgrade their shells. Interruptions can aggravate the crabs, resulting in attacks against the unfortunate source of disruption.
Hermit crabs have hard exoskeletons like other crabs, but with much weaker abdomens. They find and "wear" shells as homes and protection, getting around with their front legs and claws. Surprisingly fierce, hermit crabs fight for new shells as they grow bigger, using an assortment of hollow alternatives as substitutes when shells of the right size can't be found.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
AmphibiousAn amphibious creature can breathe in water and in air, even outside of its preferred environment, usually indefinitely but at least for hours. These creatures often have a swim Speed. Their bludgeoning and slashing unarmed Strikes don't take the usual -2 penalty for being underwater.