Salad fingers is a mentally ill man who lives in some sort of wasteland / refuge for the insane. his only companions are his equaly crazy neighbors and a few sock puppets. He enjoys the feel of rusty metals and that has replaced sex in his psyche. He probally got his name from noting that his fingers were solid and confused it with "salad".
Salad fingers: "I love the feeling of rusty spoons, it's almost orgasmic"