- "Ah, nothing like a good Antarean Bogg morph for... taking a bite out of your enemies."
- ―Visser Three
An Antarean Bogg is an alien species of unknown origin.
- "As we watched, Visser Three began to morph. His Andalite head grew large, larger. Much larger. The four horselike legs merged into two and then expanded, each leg becoming as big around as a redwood tree. The delicate Andalite arms sprouted and became tentacles. [...] In the hideously bloated head, a mouth appeared. It was filled with teeth as long as your arm. The mouth grew wider and wider, becoming a monstrous, terrifying grin. There was nothing left of the Andalite body, A monster had taken its place."
Based on Jake's description in The Invasion when witnessing Visser Three morphed into one, Antarean Bogg are huge and monstrous alien creatures with two legs that are as big and as round as at redwood tree, a huge bloated head with a wide, monstrous mouth filled with teeth as long as a human arm, and thick tentacles for arms. In TV Series however, their appearance changed into a humanoid reptilian beast that greatly resembles Hork-Bajir, except that they have shorter neck and more lizard-like head.
Visser Three uses Antarean Bogg morph to kill Elfangor in the same manner in the book, though he doesn't need to had some Controller's help to restrain the Andalite as the Andalite is already dying. He later used it again when one of his Controller servants insults him.