BeastCut is an ability that has so far only appeared in some of the Dragon Quest Monsters games. It does 50% damage to beast enemies and costs 3 MP. It's very similar to Cattle Prod from Dragon Quest IX, but has a different name in Japanese.
Called BeastCut in this game, this ability can be learned by various monsters. It requires the monster to be at least level 12, with at least 62 HP, 68 strength, and 72 agility. It is naturally learned by the FloraJay, GiantWorm, LizardMan, MadKnight and SlimeNite.