Looney Tunes and Hanna-Barbera Ultimate Crossover Crisis: A Collision of Two Worlds

Looney Tunes and Hanna-Barbera Ultimate Crossover Crisis: A Collision of Two Worlds is a crossover comic book series published by DC Comics, based on the Looney Tunes/Merrie Melodies franchise, on the Hanna-Barbera animated universe and on the Tom and Jerry/MGM Cartoons universe.

Looney Tunes/Merrie Melodies

 * Bugs Bunny
 * Lola Bunny
 * Daffy Duck
 * Tina Russo Duck
 * Porky Pig
 * Petunia Pig
 * Sylvester Pussycat
 * Sylvester Junior
 * Tweety Bird
 * Speedy Gonzales
 * Slowpoke Rodriguez
 * Hippety Hopper
 * Granny
 * Hector the Bulldog
 * Foghorn Leghorn
 * Barnyard Dawg
 * Henery Hawk
 * Wile E. Coyote
 * Road Runner
 * Pepé Le Pew
 * Penelope Pussycat
 * Hubie and Bertie
 * Claude Cat
 * Mac and Tosh Gopher
 * Marc Anthony and Pussyfoot
 * Charlie Dog
 * The Three Bears
 * Elmer Fudd
 * Yosemite Sam
 * Marvin the Martian
 * K-9
 * Rocky and Mugsy
 * Witch Hazel
 * Gossamer
 * Cecil Turtle
 * Beaky Buzzard
 * Count Bloodcount
 * Hugo the Abominable Snowman

Tiny Toon Adventures

 * Buster Bunny
 * Babs Bunny
 * Plucky Duck
 * Shirley the Loon
 * Hamton J. Pig
 * Gogo Dodo
 * Furrball
 * Sweetie
 * Li'l Sneezer
 * Fowlmouth
 * Calamity Coyote
 * Little Beeper
 * Fifi La Fume
 * Elmyra Duff
 * Montana Max
 * Marcia the Martian
 * Arnold the Pitbull

Animaniacs

 * Yakko, Wakko and Dot Warner
 * Dr. Otto Scratchansniff
 * Thaddeus Plotz
 * Hello Nurse
 * Ralph the Guard
 * Slappy and Skippy Squirrel
 * Rita and Runt
 * Minerva Mink
 * The Goodfeathers
 * Buttons and Mindy
 * Pinky and the Brain

Yogi and Friends

 * Yogi Bear
 * Cindy Bear
 * Boo-Boo Bear
 * Ranger Smith
 * Huckleberry Hound
 * Snagglepuss
 * Quick Draw McGraw and Baba Looey
 * Top Cat, Benny the Ball, Spook, Choo Choo, Fancy Fancy and the Brain
 * Augie Doggie and Doggie Daddy
 * Wally Gator
 * Pixie and Dixie
 * Mr. Jinks
 * Ruff and Reddy
 * Secret Squirrel and Morocco Mole
 * Atom Ant
 * Magilla Gorilla
 * Snooper and Blabber
 * Peter Potamus and So-So
 * Yakky Doodle
 * Hokey Wolf and Ding-A-Ling
 * Ricochet Rabbit & Droop-a-Long
 * Touché Turtle and Dum Dum
 * Lippy the Lion & Hardy Har
 * Grape Ape and Beegle Beagle
 * Penelope Pitstop
 * Captain Caveman
 * Loopy De Loop
 * The Hillbilly Bears
 * Dick Dastardly and Muttley

The Flintstones

 * Fred Flintstone
 * Wilma Flintstone
 * Pebbles Flintstone
 * Dino
 * Barney Rubble
 * Betty Rubble
 * Bamm-Bamm Rubble
 * Hoppy
 * Mr. Slate

The Jetsons

 * George Jetson
 * Jane Jetson
 * Elroy Jetson
 * Judy Jetson
 * Astro
 * Rosie the Robot Maid
 * Mr. Spacely

Scooby-Doo

 * Scooby-Doo
 * Shaggy Rogers
 * Fred Jones
 * Daphne Blake
 * Velma Dinkley

Jonny Quest

 * Jonny Quest
 * Dr. Benton Quest
 * Race Bannon
 * Hadji
 * Bandit

Tom and Jerry/MGM Cartoons

 * Tom Cat
 * Jerry Mouse
 * Tuffy Mouse
 * Spike and Tyke Bulldog
 * Butch Cat
 * Droopy and Dripple
 * McWolf
 * Miss Vavoom
 * Screwy Squirrel
 * Barney Bear

Trivia

 * Despite the fact of the copyrights for Tom and Jerry and MGM Cartoons currently belonging to Turner Entertainment (also owned by Time Warner), these characters were included in the series due the fact of William Hanna and Joseph Barbera creating the former and directing various cartoons from the latter.