Jippy is a CPU Mii who looks like a dog.
Wii Sports
In Tennis his level is 99999 and plays mostly with Xavier or Miguel X. In Baseball his level is 99999 and has himself, Misaki 2, Momel, Misy, Noval, Nellie, Ay, Fatso, and Sakura. In Boxing, his level is 99999 and is almost impossible to beat. You have to punch in the legs, because that's where his "weak spot" is. But that's still pretty hard to get to.
Wii Sports Resort
In Swordplay Duel and Speed Slice his level is unknown, but he is a really fast opponent. In Showdown he is the boss of secret level 28. In Basketball, his level is 12999 and he's the champion. In Table Tennis his level is unknown.