Simplify the following text for a Grade 8 native English-speaking person.
Original: This category is for Disney characters that primarily ( or exclusively ) appear in the Mickey Mouse universe . The Mickey Mouse universe is separated from the other main Disney universe ( i.e. the Donald Duck universe ) by rarely featuring Donald or any members of his extended family ( such as Scrooge McDuck ) , and instead revolving around Mickey and Minnie Mouse , as well as Goofy and various other characters with which they interact .
Simplified: These are Mickey Mouse universe characters .