Although we all know Wacky Packs to be the original big source of product parodies, I realized the other day where I actually saw some, which pre-dated Wacky Packs by 20+ years. It was in the original Bugs Bunny cartoons. Specifically, my favorite one, Baseball Bugs from 1946.
As seen in the backdrop, product spoofs are shown clearly all around the field. Including the iconic scene of the fielder getting his cigar pushed into his mouth by the ball with the words on the billboard saying "does your tobacco taste different lately?". This was the true introduction to product parody on a big scale and probably had a significant influence on why many of us were drawn to wacky packages. BB cartoons were very ar with kids in the early 1970's (in my neck of the woods anyway).