Hugh Jackman A.K.A Wolverine Appears In X-Men: First Class
Along with a unknown mystery cameo from a actress in the first three X-Films is one of most popular X-Men,Wolverine with a reprised role from Hugh Jackman.
Although not a big part (it is a cameo) he will appear in a scene as described here:
"Half way through X-Men: First Class, as Professor X and Magneto are travelling the world looking for mutants, they come across Wolverine, played by Hugh Jackman, in a bar. Before they can get a sentence out, Wolverine, without looking at them tells them to “Go [frick] yourselves.” They leave. "