Wily Kat and his twin sister,
Wily Kit, are the
mischief makers of the
Thundercats. They fly around on
hoverboards and use their handy
bags of tricks to confuse and bewilder their opponents. Although initially appearing the same age as
Lion-O, when he aged on the trip from
Thundera to
Third Earth, they did not appear to (or it affected them less).
Wily Kat tends to be the leader of the two, but he also tends to lead them into trouble. That whole "Curiosity killed the cat" thing. If not for the other Thundercats, and the typical luck of being children, the twins would probably have been caught a long time ago.