El Vez is "The Mexican Elvis", singing songs about life and fun that are both original and derived from other tunes. I saw him in concert about 15 or so years ago at a Christmas show in the SF Bay Area and it was awesome! I still have my signed copy of "Merry Mex-Mas" (Amazon MP3 Download) from that show and we break it out every year.
Here a video of the live show, singing "Feliz Navidad" and a couple more songs. As an added bonus, I've appended a short documentary on the man himself. Enjoy!