
The mummy face image I used to illustrate the post about my daughter's story is from the
Frankenstein Sticker series by
Topps (1966),

which were labeled 'Frankenstein Valentines' on the box and were, indeed, horrible love notes. Topps is probably best known for their
Wacky Packages stickers, which are also pretty monsterous, but the
Monster stickers are (duh!) my favourite, with pencil art by Jack Davis and Wally Wood, and finished paintings by Norm Saunders.

I'm a big fan of the
Mars Attacks! and
Batman cards from the same period,

but my runner up series would have to be the
Ugly Stickers (1965) and Buttons (1967), with more sick art by Wood, Saunders, and Basil Wolverton. Talk about a golden age of creep!