Life of the Party

Card text

First strike, trample, haste

Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of creatures you control.

When this creature enters, if it's not a token, each opponent creates a token that's a copy of it. The tokens are goaded for the rest of the game. (They attack each combat if able and attack a player other than you if able.)