The little taqueria down on the corner by my house sells calf brain tacos. Never been drunk enough, yet...
Most of the Mom n Pop Mexican restaraunts around sell all the "strange stuff" as it's part of their culture to use the entire carcass. Menudo from tripe, beef tongue, etc. Barbacoa is a traditional BBQ dish made by wrapping the head in burlap and slow cooking in a hole in the ground full of hot coals overnight. Then they scrape the meat off the skull. It hought it was rather sweet, kind of weird tasting to me. But the iguana I ate in Trinidad was the weirdest thing in taste and origin I ever ate...