Krenko is reds the most popular, and possibly the strongest commander. Krenko creates massive amount of goblins, doubling the amount of Goblins you control with every single tap. Krenko decks are extremely aggressive, and can flood the battlefield in a heart beat.
Goblins are reds main creature type and gets new support from almost every set. Goblin tribals focus to create many 1/1 goblin tokens and make them bigger with Goblin lords, buffing them up and giving them haste. Often the decks run multiple different sac outlets to either burn players or receive extra value from the tokens.