The Cheetos Mouse made the scene around 1971, pitching for Cheetos chips. Actually they don't call them chips, rather "cheese flavored snacks", but we all know what they are. Anyway, they were called "Chee-tos" then (with a dash), and came in crunchy or baked puffs.
The Cheetos Mouse was a rather sophisticated, well-spoken mouse, who yearned for the crunch of his beloved Chee-tos.
In 1973 Cheetos gave away the wonderful pencil topper Mouse premiums in six-packs of single-serving bags. They came in several colors, shown here in green. This was the last in a series of pencil toppers from Frito-Lay (makers of Cheetos), following The Frito Bandito, The Fritos Muncha Bunch and W.C. Frito.
Yes, Cheetos -- "The cheese that goes CRUNCH".
Here's an actual commercial cel from the "Hail Chee-sar" Caesar spoof commercial.
There's a vintage commercial you can see on-line at RetroJunk.com. Very cool.
Here are a few premiums that I've spotted here and there. In addition to the pencil topper, there was a plush Mouse, several different packets of vegetable or flower seeds (yes, really), and an odd Cheesy Rider belt buckle of unknown origin -- perhaps an in-house item.
There were also box panels to color, from the six-pack tray. I have one, and need to scan it in someday.
As far as I can tell, the Cheetos Mouse disappeared in the late 1970s. Frito-Lay created Chester Cheetah in 1986 to represent Cheetos, and he's been there ever since.
Well 30 years later, I still say: "Hail Chee-sar!" to the king of cheesy snacks.