A vagina, or taco, that is toxic. Usually ridden with multiple STDs, it's very gross, and is similar to muff cabbage. Also anything from Taco Bell, or Taco Bueno.
Damn! That whore had a really toxic taco!
The result of ingesting Mexican food, mainly Taco Bell
Aw man, shouldn't have eaten that Taco, that shit's giving me Toxic Taco Gas