Batman has faced countless formidable opponents in his eventful history, from the Joker and the Riddler to Killer Croc and Clayface. He's also been involved in a number of crossovers with characters from other franchises. In these crossovers, he has faced the likes of the Predators, the Aliens, Judge Dredd and Wolverine. This made me think about other characters from non-DC sources who would make good opponents for him. So I compiled a small list. The list takes in to consideration a number of factors: First, the character must pose a non-physical threat in some way - whether it's by virtue of being intellectually equal to Batman, or a psychological threat, or even a threat in the business world - but this would rule out people like the Master from Doctor Who, who is far superior to Batman on an intellectual level. Second, the character must pose a physical threat, without being ridiculously more powerful than Batman - this would rule out characters like Galactus who operate on a much higher scale. Third, I only wanted to choose one character from any given source, so there won't be two characters from Marvel, for instance. With that in mind, here are five great non-DC opponents for Batman...