After Jack-in-the-Box's future death, the Jackson was taken to the future by the Brothers of Trouble. There, he was trained and taught the life and words of Jack-in-the-Box. However, this mainly constited of treating Jack's wisecracks as serious domga. He intentionally transformed by some kind of mutation in a totally fanatic, feral version of his father.
He went back in time to meet his idol. Seeing his father didn't follow the teachings he was taugh in the future, he decided to kill him with the help of the Box. Jack-in-the-Box stopped them (with Jack freezing Jackson), but they swore vengeance on him before going back to their respective timelines.
He has claws. He may or may not have some form of super agility and durability. He has veins coming out of skin, which can emit acid. However, this doesn't seem to hurt him.