This version of Chameleon’s mask/face is definitely one of the creepier-looking ones.
Amazing Spider-Man (Vol. 1) #80
Published: c. November, 1969?
Cover Date: January, 1970
“On the Trail of… The Chameleon!”
Writer: Stan Lee
Artist: John Buscema, Jim Mooney, and John Romita
Inker: Jim Mooney
Letterer: Sam Rosen