Most of the villains who have appeared in the Spiderman movies have mainly been the ones who appeared on Spiderman comics. Hydroman was created after the likes of Green Goblin, Doctor Octopus and Sandman. As a visual effect, Hydroman would not be very impressive since he has too much in common with Sandman. They have similar origins, their powers are quite alike and both eschew costumes as they prefer casual clothing.
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