Composite Hulk is what happens when Impossible Man uses poppupian magic to combine the strongest ones there are! Well, you'll have to read the comics, but basically in a fight with Xemnu, the two Hulks were getting overwhelmed and were combined into one, more powerful Hulk.

I used a Marvel Select Red Hulk and resculpted part of the hair, then gave him a full repaint. Turned out surprisingly cool.