From Wikipedia:
"When the character of Snagglepuss was used for a series of Kellogg's cereal television commercials in the 1960s, Bert Lahr filed a lawsuit, claiming that the similarity of the Snagglepuss voice to his own might cause viewers to falsely conclude that Lahr was endorsing the product. As part of the settlement, the disclaimer "Snagglepuss voice by Daws Butler" was required to appear on each commercial, thus making Butler one of the few voice artists to receive a screen credit in a TV commercial."

Some guy: A snack would go good right now.

Satan (Appears in a cloud of brimstone.): How about a Lay's potato chip? Betcha can't just eat one.

SG: This is good.

S: How about another, then your soul is forfeit to me! (Laughs manically.)

SG: Wait, let me get this straight. I face eternal damnation not for vast wealth, power, beautiful women, or forbidden knowledge, but for just some lousy potato chips? I could buy my own bag. Even two bags.

S: Yes, I suppose you could–

SG: Bye, Satan.

S: But–

SG: I said take off!

A 50 year old commercial convinced me I needed potato chips today.