The first boss battle in Ar tonelico: Melody of Elemia, these enemies also serve as a sort-of preview of the more advanced Beast-type enemies you will encounter later on in the game, like the Night Stalkers and Mist Walkers. They only have one attack: Bite, which causes low physical damage to a single target, but what makes them an annoyance is the fact that they are immune to physical attacks, and since you won't have a Reyvateil at this point, this reduces your options of attacking them to just using the Missiles you should have Grathmelded prior to battling them.