Myr Battlesphere

When this creature enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever this creature attacks, you may tap X untapped Myr you control. If you do, this creature gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Dr. Eggman

Flying
At the beginning of your end step, draw a card. Then each opponent faces a villainous choice — That player discards a card, or you may put a Construct, Robot, or Vehicle card from your hand onto the battlefield.