Impact Tremors

Whenever a creature you control enters, this enchantment deals 1 damage to each opponent.

Kobold Taskmaster

Other Kobold creatures you control get +1/+0.

Kobold Drill Sergeant

Other Kobold creatures you control get +0/+1 and have trample.

Rograkh, Son of Rohgahh

First strike, menace, trample
Partner (You can have two commanders if both have partner.)

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Purphoros, God of the Forge

Indestructible
As long as your devotion to red is less than five, Purphoros isn't a creature.
Whenever another creature you control enters, Purphoros deals 2 damage to each opponent.
{2}{R}: Creatures you control get +1/+0 until end of turn.

Kobolds of Kher Keep

Cloudstone Curio

Whenever a nonartifact permanent you control enters, you may return another permanent you control that shares a permanent type with it to its owner's hand.

Mountain

Crimson Kobolds

Kobold Overlord

First strike
Other Kobold creatures you control have first strike.

Crookshank Kobolds

Rosnakht, Heir of Rohgahh

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Heroic — Whenever you cast a spell that targets Rosnakht, Heir of Rohgahh, create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Kher Keep

{T}: Add {C}.
{1}{R}, {T}: Create a 0/1 red Kobold creature token named Kobolds of Kher Keep.