Call of the Wildkin

Whenever a creature attacks alone, reveal cards from the
top of your library until you reveal a creature card. Put
that card onto the battlefield tapped and attacking, then
shuffle the rest into your library. If that creature has power
6 or greater, it gains trample and haste until end of turn.

Sacrifice Call of the Wildkin: Creatures you control fight
up to one target creature you don’t control.

Some call it madness. Hans calls it a warm-up.