4. Blowing His Fingers Off
Peter badly injures himself through sheer stupidity in the episode "Whistle While Your Wife Works". When Quagmire returns home from a holiday in Florida, he heads to the Griffins' house to tell Peter that he has smuggled some fireworks into Quahog by hiding them in his anus (as you do...). Peter tells him that fireworks aren't illegal in Quahog, so he didn't need to hide them and could have just brought them in normally, but Quagmire doesn't see any fun in doing that and dismisses the idea. Later on, the Griffins and Quagmire start to play with the fireworks. Peter attaches ten M-80s together to create a "bunker busting mega ultra super" firework and shows Quagmire them (while they are lit), but they explode, detaching all the fingers from his right hand. Unfortunately, with Joe's help, Peter is able to find his fingers and later gets them reattached to his hand, so yet again he doesn't learn his lesson.