Chimera Trois

Chimera Trois (キメラトロワ Kimera Torowa) is a Dark Guild that resides in the Three-Headed Mountain. It is composed solely of three members, but their strength rivals that of an entire guild. They are known for their Chimera Technique, when they fuse their bodies to create a giant strong beast, with the stength of one of Zeref's creations.

Trivia

 * "Trois" is French for "three".