This is the BIG one!
Another great thing to do at your local library is have a dig through the newspaper collections. On a recent look through local press I found this 1962 advertising strip for the monster movie "Gorgo"

Quite nice actually. I wonder who drew it? I remember strips like this advertising movies 20 years later for things like "Clash of the Titans".
This paper had another delighful feature. Design Gorgo's head.

Looks like the same artist. I got curious and a referral to Phil Hardy's Encyclopedia of Science Fiction Movies got me a look at a photo of the big monster.

Comics were used a lot more in the past to advertise anything and everything. I'm looking forward to chancing upon more of them.