The most obscure pun in Asterix; the first comic strip character; the Scrabble-like game using comics instead of letters; and the comic that can be read upside-down.

The French comic book Asterix and Cleopatra contains what is perhaps the most obscure pun in that series’ history.

In 1867, Ally Sloper became the first reoccurring comic book character in history.
Scroubabble is a French game modelled after Scrabble – but using comic book panes instead of letters.

The Upside Downs of Little Lady Lovekins and Old Man Muffaroo, first published in 1903, was an ambigram comic: it could be read upside down.