Bull Aurochs

Trample
Whenever Bull Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Rimehorn Aurochs

Trample
Whenever Rimehorn Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.
{2}{S}: Target creature blocks target creature this turn if able. ({S} can be paid with one mana from a snow source.)

Bloodline Pretender

Changeling (This card is every creature type.)
As Bloodline Pretender enters, choose a creature type.
Whenever another creature you control of the chosen type enters, put a +1/+1 counter on Bloodline Pretender.

Aurochs

Trample
Whenever Aurochs attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Aurochs Herd

Trample
When Aurochs Herd enters, you may search your library for an Aurochs card, reveal it, put it into your hand, then shuffle.
Whenever Aurochs Herd attacks, it gets +1/+0 until end of turn for each other attacking Aurochs.

Adaptive Automaton

As Adaptive Automaton enters, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.