Calvin and Hobbes were seen playing Scrabble in two strips (12/14 1986 and 2/28 1990)
Calvin asked Hobbes how many points he got from the word "be" Upon hearing that it was only worth two points, Calvin yelled, "2 points?! Is that ***** all??" , whereupon Hobbes remarked, "My, this game does teach new words!" Hobbes then went on to spell "zygomorphic" on a triple word score box for 150 points. Calvin took the "i" from Hobbes' word to spell "in" (3 points). Then, Hobbes took the "n" to spell "nucleoplasm" for 40 points, at which point Calvin kicked the board over and they played poker instead.
In this strip, Calvin spelt the word "Zqfmgb" on a double word score box. Hobbes said that "Zqfmgb" wasn't a word and threatened to look it up, but Calvin retorted that he would look up another word that Hobbes had made with all the X's and J's. Hobbes then relented and asked for Calvin's score, which Calvin reported as 957 points.