This creature appears as a semi-solid cloud of vapor and mist.
AC 23, touch 17, flat-footed 16 (+6 Dex, +1 dodge, +6 natural)
Speed 20 ft., fly 20 ft. (good)
Str 12, Dex 22, Con 14, Int 14, Wis 14, Cha 13
A mihstu deals 1d2 points of Constitution damage to an engulfed opponent each round the hold is maintained.
A mihstu can try to wrap a Medium or smaller creature in its body as a standard action. The mihstu attempts a grapple that does not provoke an attack of opportunity. If it wins the grapple check, it establishes a hold and can slash (with a tentacle) the engulfed victim with a +4 bonus on its attack roll. It can still use its tentacles to strike at other targets.
Attacks that hit an engulfing mihstu deal half their damage to the monster and half to the trapped victim.
Ranged attacks (including magic missile) used against a mihstu have a 50% miss chance.
Cold-based attacks and effects deal no damage to a mihstu, but stun it. If the cold-based effect allows a saving throw and the mihstu succeeds on its save, it ignores the stun effect. If it fails its save, or if the effect doesn't allow a save, the mihstu is stunned for 1d4+2 rounds.