It appears to be a two headed worm, one head is female, has a pink color and is named Gretel, the other is male that has a blue colored head who is named Hansel.
The male head seems to be more active than the female head, being the one who makes rocks fall onto Giana. Hansel and Gretel has 3 HP. When the moving platform is below the boss, the player must twist in the right moment to bring out a spike and damaging Hansel and Gretel. When defeated, it lies limp on the ground, while diamonds pour out of it.