The western was in a bit of a cul-de-sac by the early 70's. The spaghetti and revisionist strands had pushed the format to its extremes, meaning that not much new territory was pursued. Pancho Villa was neither spaghetti, nor a revisionist; it was a Spanish western which decided that the best foot forward was to play things for laughs. It traded largely on its star actor Telly Savalas who was a massive TV star at the time as a result of Kojack.
The result is a silly and often tedious biopic about the Mexican revolutionary of the title and is specifically about his mini-invasion of the U.S.A. in 1916. I don't know the real story but it's quite obvious that this is a loose retelling at best. There is a lot of very stupid humour here including ludicrous separate scenes involving a fly and a lizard. The humour really isn't very good so these scenes just come across as misguided. To ramp up the campy nature further the army officer who is Pancho Villa's adversary is played by Chuck Connors in a quite deranged fashion. Despite a promising opening half, things get bogged down when the Mexicans enter America and things do drag quite a bit thereafter. It is a somewhat strange movie so is possibly worth watching for that reason if you are inclined enough. It ends with Savalas crooning a song over the end credits.