Children's Science Fiction. Aliens try and save homeworld from different aliens. Read around 1997-1998.

[Erik]

There are aliens and I think they are trying to save their homeworld. There are some alien animals, monsters, or pets called fuzzy grumpers. I do not remember much else besides that.
It was a children's chapter book. It was part of a series I think. I read the books around 1998-1997 in the fourth grade. They were not much older than that, and that I really enjoyed it.