Spectacular Spider-Man (1976 1st Series) #40

"The Terrible Turnabout!" Script by Bill Mantlo. Pencils by Frank Springer. Inks by Richard Villamonte. Cover by Al Milgrom and Joe Rubinstein.

In a stunning turn of events, the Amazing Spider-Man has been transformed into the Spider-Lizard! Dr. Curt Connors is going to do everything he can to help the web-slinger, but will it be enough? New York's finest battle the Spider-Lizard and force the confused creature into the sewer system. And that's where Dr. Connors makes his final stand! Meanwhile, Electro joins the Wizard, Sandman, and Trapster to complete the new Frightful Four. 

32 pages. Cover price $0.40.