Bob Rivers
Bob Rivers is a well-known American rock and roll radio on air personality in the Pacific Northwest as well as a prolific producer of parody songs, most famous for his Christmas song parodies.
The Other Wiki has an extensive article. He has his own website. He can be heard on-air weekday mornings by clicking the listen button on the radio station's website. Interestingly, He's also a Contest Winner Cameo on an episode of Star Trek Enterprise.
His work is often credited to "Weird Al" Yankovic, despite containing lyrics and themes that Al has said he will never use (an entire song about But You Screw One Sheep! and drug references ("What if god smoked cannabis?"))