Halana, Kessig Ranger

Reach
Whenever another creature you control enters, you may pay {2}. When you do, that creature deals damage equal to its power to target creature.
Partner (You can have two commanders if both have partner.)

Rosie Cotton of South Lane

When Rosie Cotton enters, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you create a token, put a +1/+1 counter on target creature you control other than Rosie Cotton.

Mowu, Loyal Companion

Vigilance, trample
If one or more +1/+1 counters would be put on Mowu, that many plus one +1/+1 counters are put on it instead.

Jasmine Boreal of the Seven

{T}: Add {G}{W}. Spend this mana only to cast creature spells with no abilities.
Creatures you control with no abilities can't be blocked by creatures with abilities.

Kongming, "Sleeping Dragon"

Trelasarra, Moon Dancer

Whenever you gain life, put a +1/+1 counter on Trelasarra and scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Keleth, Sunmane Familiar

Whenever a commander you control attacks, put a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Anafenza, Kin-Tree Spirit

Whenever another nontoken creature you control enters, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

Queen Allenal of Ruadach

Queen Allenal of Ruadach's power and toughness are each equal to the number of creatures you control.
If one or more creature tokens would be created under your control, those tokens plus a 1/1 white Soldier creature token are created instead.

Shanna, Sisay's Legacy

Shanna can't be the target of abilities your opponents control.
Shanna gets +1/+1 for each creature you control.

Cadira, Caller of the Small

Trample
Whenever Cadira deals combat damage to a player, for each token you control, create a 1/1 white Rabbit creature token.

Maja, Bretagard Protector

Other creatures you control get +1/+1.
Landfall — Whenever a land you control enters, create a 1/1 white Human Warrior creature token.

Grunn, the Lonely King

Kicker {3} (You may pay an additional {3} as you cast this spell.)
If Grunn was kicked, it enters with five +1/+1 counters on it.
Whenever Grunn attacks alone, double its power and toughness until end of turn.

Numa, Joraga Chieftain

At the beginning of combat on your turn, you may pay {X}{X}. When you do, distribute X +1/+1 counters among any number of target Elves.
Partner (You can have two commanders if both have partner.)

Hamza, Guardian of Arashin

This spell costs {1} less to cast for each creature you control with a +1/+1 counter on it.
Creature spells you cast cost {1} less to cast for each creature you control with a +1/+1 counter on it.

Rishkar, Peema Renegade

When Rishkar enters, put a +1/+1 counter on each of up to two target creatures.
Each creature you control with a counter on it has "{T}: Add {G}."

Lulu, Loyal Hollyphant

Flying
At the beginning of your end step, if a permanent you controlled left the battlefield this turn, put a +1/+1 counter on each tapped creature you control, then untap them.
Choose a Background (You can have a Background as a second commander.)

Pianna, Nomad Captain

Whenever Pianna attacks, attacking creatures get +1/+1 until end of turn.

Alharu, Solemn Ritualist

When Alharu enters, put a +1/+1 counter on each of up to two other target creatures.
Whenever a nontoken creature you control with a +1/+1 counter on it dies, create a 1/1 white Spirit creature token with flying.
Partner (You can have two commanders if both have partner.)

Oviya Pashiri, Sage Lifecrafter

{2}{G}, {T}: Create a 1/1 colorless Servo artifact creature token.
{4}{G}, {T}: Create an X/X colorless Construct artifact creature token, where X is the number of creatures you control.

Slurrk, All-Ingesting

Slurrk enters with five +1/+1 counters on it.
Whenever Slurrk or another creature you control dies, if it had a +1/+1 counter on it, put a +1/+1 counter on each creature you control that has a +1/+1 counter on it.
Partner (You can have two commanders if both have partner.)

Surrak, the Hunt Caller

Formidable — At the beginning of combat on your turn, if creatures you control have total power 8 or greater, target creature you control gains haste until end of turn. (It can attack and {T} no matter when it came under your control.)