Free For All Heroes vs. Villains War Tournament:
Origin and fight against Batman:
After Norman Osborn made a agreement with Hammerhead (who was on the behalf of his boss: Tombstone from his behalf of his allies in The Billionaires of Crime) and hiring extra help from Dr. Drakken to aid him and Doctor Octopus (also known as: Doctor Otto Octavius at this point because he doesn't become Dr. Octopus yet) to start developing some Super Villains to keep some heroes from the Justice League and the Avengers at bay so they wouldn't other Super Villains alliances' plans. So Hammerhead brings Flint Marko to become the Sandman. But something went wrong with the experiment on Flint Marko causing him to explode but then take shape in the form of sand. Later Dr. Drakken decides to give Flint Marko (now known as Sandman) as test run by creating a bank robbery. Sandman feels outraged from the damage from the experiment abandons Dr. Drakken which Drakken was worried at first until Hammerhead assures him the next experiment would make up from the damage of the creation of Sandman. Meanwhile Sandman successfully robs a national bank until Batman arrives and battles him head on and Sandman was about to gain the upper hand until Batman knocked him out with a powerful punch leaving Sandman knocked out and Batman prepares to take Sandman to jail.