Glow Worm

WARNING: When facing these creatures, it is vital to kill/disable them before they can hit you. With the exclusion of Evolution, who can restore herself by transforming, this creature's default attack will PERMANENTLY lower the target's mana, with no way of regaining the lost stats.

The SuckMana makes them dangerous as an enemy, but as an ally it's quite average. They can sacrifice max mana to increase Magic, but it's only used for their Regenerate and nothing else. Since they have all four skills fixed you can't even give them another spell. Best avoided altogether, unless you want to make a team of worms.