Crackpot Prodigy

Autonomous -- Discard a card (This creature can't
attack or block. At the beginning of each opponent's
upkeep, that player may discard a card. If they do,
they gain control of Crackpot Prodigy and untap it.)
At the end of your turn, put an insanity counter
on Crackpot Prodigy, then target player puts the
top X cards of their library into their graveyard,
where X is the number of insanity counters on
Crackpot Prodigy.