The Lord Of Mice

If a black creature would enter the battlefield and
has a casting cost of 3 or more mana, it becomes a
2/2 white cat token. If it's casting cost is under 3
mana, put it in owner's graveyard.
If a black instant or sorcery card is played, remove
it from the game. The owner of that card creates
a 1/1 mouse token with defender.