Alright, if you’ve never heard of this comic it’s probably because you do not live in the Spanish-speaking world.  Although, I guess I have no excuse since the United States is technically now a part of the Spanish-speaking world.  Anyway, Captain Thunder and the Holy Grail (or Capitan Trueno Y El Sancto Grial) is a Spanish-language comic first released in 1956, and written by Victor Mora.

Capitan Trueno Y El Sancto Grial tells the story of a knight (hint: his name is in the title) that lives in the Middle Ages and fights various baddies in his attempt to find that elusive holy grail.  The film was produced by Bueno Vista International and stars Sergio Peris-Mencheta in the title role.