Peanuts is a syndicated daily and Sunday comic strip written and illustrated by Charles M. Schulz, which ran from October 2, 1950, to February 13, 2000 (the day after Schulz's death), continuing in reruns afterward. The strip is considered to be one of the most popular and influential in the history of the medium, with 17,897 strips published in all. It chronicles the adventures of unlucky boy named Charlie Brown, and his lovable dog, Snoopy.
In "E. Peterbus Unum", when the guys are saying what they got with their tax return, Charlie Brown, dressed unconvincingly as a ghost, said "I got a rock", referring to the Halloween special where he kept getting rocks instead of candy.
After he is fired from his job at The New Yorker, Brian encounters a “No Dogs Allowed” sign, hears a booming voice enforcing the rule and then lays on top of a doghouse. This parodies the Peanuts character Snoopy in the 1972 film Snoopy, Come Home.
Charlie also appears in "Mother Tucker", grown up and behaving abominably at the Peanuts reunion where his guest is a coarse skanky crackwhore. He breaks down in tears because Snoopy and Woodstock are dead, the strong implication being that he had supplied the drugs to them which led to their demise. He makes things worse by claiming that he doesn't care about Woodstock, but that Snoopy did not deserve it.
When Herbert gets a bath from Meg instead of Chris in "Play It Again, Brian", he exclaims "Aww rats!" in the same manner as Charlie Brown.