Cruller is an enemy family in Final Fantasy Dimensions. It is difficult to explain what Cruller resembles. They are based on enemies in Final Fantasy VI, in this game one is referred to as mollusk-like, and the other as a bizarre monstrosity. Even the enemy's names do not give much away; Cruller's Japanese name is dudufedu (ドゥドゥフェドゥ?) which is just nonsense, and Enuo's supposed name origin does not seem to link up with its appearance.
The enemy whose name is not from a previous game, Fused Organ, is simply called "organ" in Japanese, and called "entrails" in French. Therefore perhaps we could say the species are some form of animated organs.