Magic Beast

Magic Beast (魔獣) is a term that refers to Monsters closely related to or evolved from animals, making up the large majority of Monsters seen in the series.

Mystic Beast
Mystic Beasts (妖獣) are something like a sub-category of Magic Beasts. Mystic Beasts get their nutrition almost entirely from Magicules, while ordinary Magic Beasts supplement their diet mainly with meat and plants like regular animals.