Danger Mouse is a fake CPU Mii from Wii Sports, Wii Sports Resort and Wii Party. His overall skill level is 967.
In Tennis, his level is 1278 so he is a PRO and doubles with Penfold. In Baseball, he is a Superstar Class player and his skill level is 2859-2995. He appears on the teams of John and some other ones. In Boxing, his level is 1012-1144 and he is a PRO.
Wii Sports Resort
In Wii Sports Resort, his skills seem to fall. In Swordplay Duel and Speed Slice, he is very bad and his skill level is 184. In Basketball, his level is 741 and plays with Penfold and Professor Squawkencluck. In Table Tennis, his level is 608 and he is good.
In Wii Party, Danger Mouse is a Beginner Mii.