Minecraft Dungeons:Baby Ghast

The Baby Ghast is a pet mob $$ obtained through the Flames of the Nether DLC. It is purely cosmetic and does not attack enemies, nor do any enemies target it.

Appearance
The Baby Ghast is a juvenile form of the ghast. They are characterized by having small white translucent bodies with a red core inside, a small mouth, red eyes, and small tentacles, making its appearance akin to a jellyfish. The whole body of the Baby Ghast is smaller and almost the size of the player's head and it also disappears when you are away and appears when you are close.

Trivia

 * The Baby Ghast is currently the only pet that is based on a hostile mob.