Here it says he is voiced by both Jason Earles and Gabriel Iglesias: http://empeorsneworld.wikia.com/wiki/Guaka
Gabriel even said his work on the show was his favorite VA work, but he said he voiced twins here: http://www.lasvegasweekly.com/news/2009/jul/23/gabriel-iglesias-fabulously-fluffy/ I can only think of Zim and Zam, who were voiced by the Sprouse twins. It's all so confusing.