I am unsure how these golems made out of blocks are called but sometimes they leave blocks stuck in the air, it's impossible to remove them so they're just stuck entities.

Already fixed for the upcoming release: https://github.com/ACGaming/MoCreaturesExtended/blob/b55ac0baa15abc0130701d824e8a3f426f91c84b/src/main/java/drzhark/mocreatures/entity/item/MoCEntityThrowableRock.java#L117