The Bag man Spiderman suit first appeared on Amazing SPIDER-MAN #258.
Spidey heads around to the Fantastic Four building, so that Reed Richards can have a look at his new black costume, which has been acting a bit strangely. When it turns out to be an alien symbiote, they remove it post-haste, leaving Peter with nothing to protect his secret identity. The Human Torch Johnny Storm kindly lent Spidey an old Fantastic Four costume, with a brown paper bag for a mask and a “Kick Me” sign on the back.
Peter Parker has a lot of Spiderman costumes, and this is one of the funniest and memorable costumes that Spider-man wore.