Ghost (Yoshi's Story)
From the Super Mario Wiki, the Mario encyclopedia
The ghost is a flying, green, snake-like enemy that appears in the final boss fight of Yoshi's Story. Baby Bowser rides on them, so if a Yoshi tries to throw an egg at Baby Bowser, the egg hits these ghosts. They are invincible, as the eggs merely bounce off of the ghosts. Instead, Yoshi has to either throw eggs at the ceiling (which is littered with spikes) to make the spikes fall down and land on Baby Bowser or explode the eggs in front of Baby Bowser's face.
Names in other languages