Snoopy has had many alter egos over the course of the fifty years of the Peanuts comic strip. Some alter egos are more famous than others, for instance The World War I Flying Ace, and Joe Cool. The following is a list of all of Snoopy's alter egos, and the date of their first appearance.
- A shark (July 21, 1954)
- A wolf (January 26, 1955)
- A rhinoceros (February 22, 1955)
- A snake (August 29, 1955)
- Violet (November 17, 1955)
- A pelican (November 21, 1955)
- Lucy (November 22, 1955)
- A moose (November 24, 1955)
- Beethoven (November 25, 1955)
- Mickey Mouse (November 26, 1955)
- A giraffe (February 7, 1956)
- A kangaroo (February 8, 1956)
- An aligator (February 28, 1956)
- A lion (May 3, 1956)
- A python (July 24, 1956)
- An elephant (September 17, 1956)
- A polar bear (February 7, 1957)
- A bird (April 14, 1957)
- A mule (July 14, 1957)
- A circus dog (July 24, 1957)
- A sea monster (August 23, 1957)
- A penguin (December 31, 1957)
- An anteater (March 1, 1958)
- A bald eagle (May 12, 1958)
- A vulture (May 13, 1958)
- A tiger (June 15, 1958)
- A goat (June 18, 1958)
- A bloodhound (March 26, 1959)
- A cow (June 14,1959)
- A baby (June 23, 1959)
- A cricket (September 12, 1959)
- A mountain lion (November 29, 1959)
- A TV antenna (January 7, 1960)
- A helicopter (March 14, 1960)
- Dracula (April 18, 1960)
- A dinosaur (July 7, 1960)
- A ship's captain (January 29, 1961)
- A rabbit (March 16, 1961)
- A gorilla (March 21, 1961)
- A lost calf (March 26, 1961)
- A salmon (October 17, 1961)
- A hood ornament (November 24, 1961)
- The chairman of the board (February 13, 1962)
- A shepherd (July 1, 1962)
- A gargoyle (September 27, 1962)
- A teddy bear (December 28, 1962)
- A weather vane (June 1, 1963)
- A sheep (December 24, 1964)
- A trapeze artist (March 2, 1965)
- A skateboard champion (March 29, 1965)
- A bowling ace (April 14, 1965)
- A surfer (August 5, 1965)
- A legionnaire in the French Foreign Legion (August 22, 1965)
- The World War I Flying Ace (October 10, 1965)
- The WWI army surgeon (November 24, 1966)
- The Masked Marvel (February 9, 1967)
- A piranha (March 25, 1967)
- A leopard (June 18, 1967)
- A secret agent (September 7, 1967)
- The World Famous Hockey Player (October 8, 1967)
- The Creature from the Sea (January 12, 1968)
- A school principal (January 30, 1968)
- The World Famous Golf Pro (April 8, 1968)
- The Easter Bunny (April 14, 1968)
- Captain of the Rescue Squad (January 27, 1969)
- A prairie dog (February 12, 1969)
- The World Famous Astronaut (March 8, 1969)
- A roller derby star (July 4, 1969)
- The WWII Veteran (November 11, 1969)
- The World Famous Quarterback (November 23, 1969)
- The World Famous Skier (December 15, 1969)
- The "Head Beagle" (February 16, 1970)
- The World Famous Tennis Star (June 11, 1970)
- The World Famous Grocery Clerk (August 25, 1970)
- The World Famous Swinger (November 30, 1970)
- The Easter Beagle (April 11, 1971)
- A sheep dog (April 25, 1971)
- Joe Cool (May 27, 1971)
- The World Famous Football Coach (September 2, 1971)
- The World Famous Swimmer (October 2, 1971)
- The World Famous Attorney (January 12, 1972)
- Captain of the Starship Enterprise (February 7, 1972)
- A pirate (August 14, 1972)
- A bat (November 10, 1972)
- A football team doctor (December 2, 1973)
- The World Famous Member of the Emergency Rescue Squad (October 9, 1974)
- Joe Motocross (May 10, 1975)
- An airplane mechanic (June 24, 1975)
- A man from the chamber of commence (July 2, 1975)
- A jogger (May 17, 1976)
- A helicopter (February 1, 1977)
- An owl (October 27, 1977)
- Peppermint Patty (December 5, 1977)
- The World Famous Disco Dancer (October 16, 1978)
- The April Fool (April 1, 1979)
- The World Famous Riverboat Gambler (May 30, 1979)
- A county surveyor (June 18, 1979)
- A scarecrow (June 22, 1979)
- A python (October 9, 1979)
- A bow and arrow hunter (January 15, 1980 )
- Dr. Beagle and Mr. Hyde (March 19, 1980)
- A rattlesnake (March 28, 1980)
- The World Famous Census Taker (March 31 1980)
- John McEnroe (May 6, 1980)
- Tracy Austin (May 7, 1980)
- John Newcombe (May 8, 1980)
- A painter (June 12, 1981)
- Joe Preppy (July 30, 1981)
- The World-Famous Hired Hand (February 27, 1982)
- The World Famous Surgeon (July 12, 1982)
- A chariot race driver (November 27, 1983)
- Flashbeagle (November 29, 1983)
- The Little Red-Haired Girl (February 10, 1985)
- A "punker" (August 7, 1985)
- The World Famous Agent (September 15, 1986)
- Alistair Beagle (June 27, 1989)
- Santa Claus (December 18, 1989)
- An "October beast" (October 2, 1990)
- The World Famous Flagman (January 9, 1991)
- A beaver (June 17, 1991)
- A trained service technician (October 10, 1991)
- An "Ace Airlines" pilot (June 8, 1992)
- Joe Grunge (April 28, 1993)
- The World Famous Hockey Coach (October 23, 1994)
- A Revolutionary War Patriot (January 5, 1997)
- The World-Famous Big-Rig Operator (March 28, 1998)
- The Scott Fitzgerald Hero (May 21, 1998)
- The World-Famous Orthopedic Surgeon (August 26, 1999)