10 Times Marvel And DC Secretly Crossed Over
8. The Hulk Beat Up Doomsday
When DC decided to kill of Superman, the writers wanted it to be at the hands of someone who was a physical match for the Man of Steel. According to rumour, the starting point for this character was "someone who is basically the Hulk" and that eventually led to the near-unstoppable killing machine Doomsday.
A few years later, Hulk got to prove who was really the strongest one there is.
Admittedly though, the version of Bruce Banner seen in The Incredible Hulk #413 was far different from the version most people are familiar with now. At the time, the Hulk actually retained the intelligence of Bruce Banner when he transformed. He was also the leader of a team called the Pantheon, a group of proactive heroes who all took their codenames from mythological figures.
In the issue, Hulk took part in a virtual reality training mission with his teammate Atalanta (named after an ancient Greek huntress). Amongst holograms of familiar faces like the Thing and Ghost Rider, Hulk can be seen smacking a figure that is mostly out of panel.
All that can be seen of the figure is an arm and a leg, but the green boot and bony spikes make it pretty obvious who it is.