Younger siblings almost always incite some initial jealousy from the kid in line before them, typically out of a fear of losing their spotlight. Thus, if we were George Little (Jonathan Lipnicki), we'd be extra tight at first too if our parents adopted a mouse of all things as our younger brother. It's bad enough that he's got to share the wealth—at least give him a sibling he can actually play catch with.
23. Stuart Little (voiced by Michael J. Fox), Stuart Little (1999)