The Amazing Spider-Man #6

In the Everglades, people started giving weird reports. Something that looked like it was part-lizard, part-man attacked people. Bullets failed to harm it. Lizard became famous all over the nation, and Spider-Man heard about him through the paper (which challenged Spidey to take the Lizard down!). Peter asked Jameson if he could go to the Glades to take photos of the Lizard (and fight him), but was flatly refused. Peter went to the Natural History museum with Liz Taylor and Flash Thompson to learn about lizards and dinosaurs, and Spider-Sensed two criminals stealing a gem. The criminals tried to kidnap Liz while Peter was changing into Spider-Man, but he effortlessly stopped them. Liz was taken with Spider-Man, but Spidey heard a broadcast daring him to fight Lizard and decided to get Jameson to let him go to the Glades. He tied J.J to the ceiling and told him he'd accept the challenge.