Sledge inks over a bikini babe in a Vectrocon poster and says "Leroy Neiman eat your heart out". Neiman, most famous for his vibrant expressionistic sports paintings, was also the creator of the Femlins for the Playboy Magazine Party Jokes page. Femlins were diminutive nude cartoon women generally shown in relation to normal sized objects and engaged in normal daily acts.
The running gag is Sledge itching all over his body. But when he pawed through the poison ivy, he was fully clothed. Unless he was shoving his hands down his pants and inside his shirt, he should only have it on his hands and wrists.
Sledge says he is immune to poison ivy. This is a case where language becomes problematic. The itching and blisters of poison ivy is caused by our hyperimmune response to the plant's oil urushiol. Our immune system responds so strongly to urushiol that our own T cells cause the rash and blisters. So, if we did not have an immune system response we would be 'immune' (nonreactive) to poison ivy.