This page explains in detail the interactions between the Peanuts series and the Garfield series.
Garfield, June 23, 1978[]
June 23, 1978

Garfield says "Happiness is a warm TV set". Jim Davis gives a nod to his inspiration for good luck.
Garfield, September 4, 1982[]
September 4, 1982

When Garfield who is dressed up as a superhero sees his teddy bear Pooky, he takes off his cape, holds Pooky and imitates the manner in which Linus holds his security blanket and sucks his thumb.
Garfield, April 8, 1983[]
April 8, 1983

In preparation for a plane trip, Garfield remarks "If a dog can be a World War I Flying Ace, I can surely fly commercial."
Garfield, March 29, 1984[]
March 29, 1984

Jon asks Garfield to fetch the paper. Garfield acts like Frankenstein's monster. Jon says to the reader "Why can't I have a normal house cat like everyone else?"
Garfield, November 29, 1984[]
November 29, 1984

When Jon bullies his brother for his blankie, Garfield imitates Linus holding his blanket and says "Careful what you say about blankies, fella."
Garfield, August 18, 1986[]
August 18, 1986

The ball that hits Garfield on the head has the pattern of Charlie Brown's shirt.
Peanuts, April 29, 1988[]
April 29, 1988

Snoopy goes to get a birthday card for the Red Baron and ponders "I wonder if he likes Garfield."
Garfield, November 14, 1988[]
November 14, 1988

Garfield sees Snoopy's reflection in a mirror in place of his own (pictured above). Davis got Sparky's permission to use Snoopy for the strip.
Garfield, February 17, 1989[]
February 17, 1989

After reading the funnies, Odie puts his bowl on his head which makes Garfield say "He's so impressionable."
Garfield and Friends episode Maine Course[]
October 21, 1989
Garfield wears Charlie Brown's shirt and baseball cap then comments "Good grief."
Garfield, January 25, 1996[]
January 25, 1996

Garfield is stuck in a tree and says "It couldn't possibly get any worse." Then a kite gets wrapped around him and someone says "Good grief!"
Garfield, September 24, 1999[]
September 24, 1999

When Jon mockingly points out Garfield sitting in a different position from earlier, Garfield asks "I wonder if Charlie Brown could use a cat?"
Garfield, May 27, 2000[]
May 27, 2000

In this strip done for Charles Schulz Day, Garfield comes upon Snoopy's doghouse and solemnly takes a nap on top of it.