Because Roger is my (everyone's) favorite MacFarlane-character, and Ricky Spanish is my favorite Roger-character.
I just love Mega-douches, I guess.
Edit: I forgot about that Albuquerque zoo discovery center shirt he's supposed to wear. Not gonna fix it because he's all in one layer and I'd just end up messing everything up, but still. Weeh.
Edit 2: Geez, he's supposed to wear rings and a bracelet too, isn't he? I'm not even gonna bring up the rest of the stuff I forgot about. Maybe I should've checked this stuff earlier.