Ayula, Queen Among Bears

Whenever another Bear enters the battlefield under your control, choose one —
• Put two +1/+1 counters on target Bear.
• Target Bear you control fights target creature you don't control.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Nature's Revolt

All lands are 2/2 creatures that are still lands.

Sol Ring

Eladamri's Call

Search your library for a creature card, reveal that card, put it into your hand, then shuffle.

Kudo, King Among Bears

Other creatures have base power and toughness 2/2 and are Bears in addition to their other types.

Sythis, Harvest's Hand

Whenever you cast an enchantment spell, you gain 1 life and draw a card.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.