Five Headed Dragon is a card from Yu-Gi-Oh!. In the English version, he is known as The Mythic Dragon. In terms of raw power, this is one of the strongest cards in the Yu-Gi-Oh! series. It is, as the card description states, summoned by fusing 5 Dragon-Type monsters and can only be destroyed through battle by a monster whose Attribute is LIGHT.
In M.U.G.E.N, Five Headed Dragon has been made by Dark Ruler.
Dark Ruler's First version
As a joke character, Five Headed Dragon only has one attack. This one-hit combo attack can cause 999 damage. He cannot be damaged, even by other joke characters, thus classifying him as a cheap character.