Rohgahh of Kher Keep

At the beginning of your upkeep, you may pay {R}{R}{R}. If you don't, tap Rohgahh and all creatures named Kobolds of Kher Keep, then an opponent gains control of them.
Creatures you control named Kobolds of Kher Keep get +2/+2.

Kobold Overlord

First strike
Other Kobold creatures you control have first strike.

Rohgahh, Kher Keep Overlord

Other Kobolds you control get +2/+2.
Whenever you cast a Kobold spell, you may pay {2}. If you do, create a 4/4 red Dragon creature token with flying.
Whenever you cast a Dragon spell, create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Kobold Drill Sergeant

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

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, create a 0/1 red Kobold creature token named Kobolds of Kher Keep.