Colchan Head of the Stampede

Trample
Whenever you attack with one or more other aurochs
you may sacrifice a snow permanent and make a token
that's a copy of target attacking creature you control that enters the battlefield tapped and attacking.
Whenever an aurochs is blocked each aurochs you
control deals damage equal to their power to the blocking creature.
Whenever Colchan attacks it gets +1/+0 until end of turn for each other attacking aurochs.