Bear

Cleaver Riot

Creatures you control gain double strike until end of turn. (They deal both first-strike and regular combat damage.)

Golden Bear

Pale Bears

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

And They Shall Know No Fear

Choose a creature type. Creatures you control of the chosen type get +1/+0 and gain indestructible until end of turn.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Runeclaw Bear

Bar the Door

Creatures you control get +0/+4 until end of turn.

Forest Bear

Wilson, Refined Grizzly

This spell can't be countered.
Vigilance, reach, trample
Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
Choose a Background (You can have a Background as a second commander.)

Goblin Oriflamme

Attacking creatures you control get +1/+0.

Crescendo of War

At the beginning of each upkeep, put a strife counter on this enchantment.
Attacking creatures get +1/+0 for each strife counter on this enchantment.
Blocking creatures you control get +1/+0 for each strife counter on this enchantment.

Grizzly Bears

Ruxa, Patient Professor

Whenever Ruxa enters or attacks, return target creature card with no abilities from your graveyard to your hand.
Creatures you control with no abilities get +1/+1.
For each creature you control with no abilities, you may have that creature assign its combat damage as though it weren't blocked.

Orcish Oriflamme

Balduvian Bears

Crash Through

Creatures you control gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)
Draw a card.

River Bear

Razorclaw Bear

Whenever this creature becomes blocked, it gets +2/+2 until end of turn.

Muraganda Petroglyphs

Bear Cub

Tuya Bearclaw

Whenever Tuya Bearclaw attacks, it gets +X/+X until end of turn, where X is the greatest power among other creatures you control.

Gruul War Chant

Attacking creatures you control get +1/+0 and have menace.

Kudo, King Among Bears

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

Copper Host Crusher

Trample
Hexproof (This creature can't be the target of spells or abilities your opponents control.)