Oh, I meant to base the fog effect on a spell (not the sleep effect). But if someone can point me at a dragon with a cloud breath weapon, I'm good to go!
Breath Weapon (Su): Cloud of superheated steam 20 feet high, 25 feet wide, and 50 feet long, once every 1d4 rounds, damage 12d6 fire, Reflex DC 21 half; effective both on the surface and underwater. The save DC is Constitution-based.
Sleeping Gas (Su): When a roosk senses the presence of living prey, it releases a cloud of gas 20 ft high, X ft wide, and X ft long. Any breathing creature within the cloud must make a DC X Fortitude save or fall asleep (regardless of HD) for X rounds. The roosk may use this ability every 1d4 rounds? The save DC is Consitution-based.
Two things: We haven't figured out a size for these things. And HTK is actually hp, not HD, so should we drop these to 2 HD?