The Green Goblin, a.k.a. Norman Osborn, kidnapped his own niece in hopes that she would know where his 'goblin serum' was hidden.  Fortunately before he was able to do any harm, Spidey stopped the Goblin, got rid of the formula and saved Mona....bad hairdo intact. 
 
 *From the episode 'Triumph of the Green Goblin'.