Mmkay, time to bring back some suggestions. This one's one of my favorites.
Name: Hydra
Stats:
Health: High
Attack: Medium, but each head attacks, so it adds up
Defense: Medium
Armour: High
Accuracy:Average
Speed:Slooow on land, fast in water
Dexterity:High
Intelligence:Low
Wage:Ridiculous
Skills:
1 Melee
for each level, gets new melee attack. Either new attack or just make cooldown time multiplied by a factor of 1/n each level, n being the new level
Information: Probably a boss creature of some kind. Starts with a certain number of heads, must be all chopped off before creature dies. It grows one new head per level (might be hard on animation, so maybe 1 head every 2 levels)
Behavior in Dungeon: I don't think this should be keeper-owned. It should be guarding some precious item or secret entrance or, even better, guarding a secret passage way to the hero's main chamber.
Also would be found in water
Jobs: None, to animal-like
Behavior in OverWorld: Won't venture to overworld much, just sticks around water in dungeons or the deep
Obtainable By: Neutral hostile, not attainable
Style: Fighter, since it's quick i'd say flanker
Hang Out Group: Perhaps tentacles could be swimming around it
Hates: Anything that disturbes it
Loves: Water
Lair: Could just recover in water
Appearance:
How Introduced: hostile definitely