Aunt Beast is one of the alien creatures that inhabits Ixchel, the planet the Murrys and Calvin land on after tessering off Camazotz.

What planet is Aunt Beast from?

For those who haven't read the book, Aunt Beast is an alien Meg meets after she, her father, and Calvin tesser off of Camazotz and away from The IT. While there, Meg befriends a very strange alien named Aunt Beast who lives on a planet called Ixchel.

Why did Meg chose the name Aunt Beast?

Why did Meg choose the name, "Aunt Beast"? Meg chose the name Aunt Beast because she is not her mother, but Meg feels as though she could be.