Es el ex novio de Minnie. Él es muy arrogante y grosero, todo lo contrario a Mickey. Aunque él dice que ama a Minnie, demuestra ser muy egoísta, como se ve en el cortometraje "Mickey's Rival", donde deja que un toro que él mismo provocó ataque a Minnie.
Cortos
Mortimer aparece por primera vez en la animación en el cortometraje "Mickey's Rival", en 1936, donde Minnie le presenta a Mickey como un antiguo novio suyo. Entonces, Mortimer empieza a hacerle jugarretas a Mickey, lo que hace que le saque de sus casillas. Luego no vuelve a aparecer hasta el cortometraje "Mickey's Rival Returns", en el 2000, donde Mortimer reta a Mickey a un partido de boleybol, en el que, quien gane, invita a Minnie a una fiesta que hay esa noche. Desde ese corto aparece en otros seis hasta el 2001.
Cómic
En los cómics, Mortimer era llamado "Montmorency Rodent" en muchas historietas. En su primera aparición era llamado "Sr. Slicker" en el cómic "Mr. Slicker and the Egg Robbers", cuando el padre de Minnie Mouse está en el peligro de perder su rancho de huevos, y el Sr. Slicker le ofrece la ayuda financiera a cambio de la mano de Minnie en matrimonio, y Mickey sospecha de él. Al final, Slicker resulta ser quien robó los huevos para conseguir la mano de Minnie. Varias veces a formado equipo con Pete el Malo o Sylvester Shyster, el cual, al igual que Mortimer, también quiere conseguir el amor de Minnie.
Otras apariciones
Mortimer aparece como personaje menor en Mickey's Once Upon a Christmas, como propietario de "Grandes Almacenes Mortimer".
Mortimer.
En la serie House of Mouse, Mortimer aparece como personaje secundario, donde se queja continuamente del espectáculo del club, intentando ridiculizar a Mickey. También se le suele ver tratando de seducir a las chicas del público, pero siempre termina en problemas.
En una ocasión apareció haciendo un cameo en un episodio de la serie de animación 3D Mickey Mouse Clubhouse. Volvió a aparecer teniendo un papel más importante en un especial de la serie, actuando como un supervillano llamado "Megamort".
Temporada Uno: "The Stolen Cartoons" • "Big Bad Wolf Daddy" • "The Three Caballeros" • "Goofy's Valentine Date" • "Unplugged Club" • "Timon and Pumbaa" • "Gone Goofy" • "Jiminy Cricket" • "Rent Day" • "Donald's Lamp Trade" • "Donald's Pumbaa Prank" • "Thanks to Minnie" • "Pluto Saves the Day"
Temporada Dos: "Daisy's Debut" • "Goofy for a Day" • "Clarabelle's Big Secret" • "The Mouse Who Came to Dinner" • "Max's New Car" • "Not So Goofy" • "Everybody Loves Mickey" • "Max's Embarrassing Date" • "Where's Minnie?" • "Super Goof" • "King Larry Swings In" • "Ladies' Night" • "Dennis the Duck" Temporada Tres: "Suddenly Hades" • "Pete's One-Man Show" • "House of Crime" • "Mickey and Minnie's Big Vacation" • "Donald and the Aracuan Bird" • "Goofy's Menu Magic" • "Music Day" • "House of Scrooge" • "Donald Wants to Fly" • "Dining Goofy" • "Chip 'n' Dale" • "Humphrey in the House" • "Ask Von Drake" • "Salute to Sports" • "Pluto vs. Figaro" • "House of Magic" • "Mickey vs. Shelby" • "House of Turkey" • "Clarabelle's Christmas List" • "Pete's Christmas Caper" • "Snow Day" • "Pete's House of Villains" • "Halloween With Hades" • "House Ghosts" • "House of Genius" • "Mickey and the Culture Clash"
Canciones
Rockin' at the House of Mouse • Mortimer Mouse • Soup or Salad, Fries or Biscuits, Extra Olives, Donuts • Bibbidi-Bobbidi-Boo • Big Bad Wolf Daddy • A Parrot's Life for Me • Let's Slay the Beast • The Ludwig Von Drake Song • It's Our House Now! • The Best Christmas of All • Grim Grinning Ghosts • Humphrey Hop • Everybody Wants to Be a Woof • I Wanna Be Like M-O-You • Pink Elephants on Parade • My Name is Panchito • Boom-Da-Boom • We Are the Three Caballeros • Me the Mouse (and I'm the Duck) (Reprise) • Daisy Crockett • The Daisy Duckie Room • Minnie Mouse (in the House)
The Annex • Mickey and Minnie's Runaway Railway • Move It! Shake It! Dance and Play It! Street Party • Vacation Fun • World of Color: Celebrate • We Love Mickey!
Temporada Uno: "Mickey's Wild Tire!" / "Sittin' Kitty" • "Goofy Gas!" / "Little Big Ape" • "Race for the Rigatoni Ribbon!" / "Roaming Around Rome" • "Agent Double-O-Goof" / "Egg-xasperating" • "Mickey's Perfecto Day!" / "Running of the Roadsters!" • "It's Wiki Wiki Time" / "Happy Hula Helpers!" • "Ye Olde Royal Heist" / "Tea Time Trouble!" • "Abra-ka-Goof!" / "Happy Birthday Helpers!" • "Guru Goofy" / "Bed, Breakfast and Bungled!" • "Going Upppppppppp!" / "Gone Fishin'!" • "Goof Luck Charm" / "Teed Off!" • "The Impossible Race" / "The Happiest Helpers Cruise!" • "Smarty Goof" / "Adventures in Buddysitting!" • "Daredevil Goofy!" / "The Big Broadcast" • "Stop That Heist!" / "Lights, Camera, HELP!" • "Mouse Vs. Machine!" / "Grandpa Beagle's Day Out" • "Donald's Garage" / "Artful Helpers" • "Ready, Get Pet... Go Pluto!" / "Figaro's New Friend!" • "Garage Alone" / "Camp Happy Helpers" • "The Haunted Hot Rod" / "Pete's Ghostly Gala" • "Billy Beagle's Tip-Top Garage" / "Diner Dog Rescue" • "Pit Stop and Go!" / "Alarm on the Farm!" • "Happy Hot Diggity Dog Holiday!" / "Happy Holiday Helpers!" • "Hot Dog Daze Afternoon" / "Super Sweet Helpers" • "The Grand Food Truck Rally" / "Cuckoo La-La" • "Rockin' Roadsters!" / "Safari, So Goody"
Temporada Dos: "The Biggest Heist Ever" / "Thrillin' Hilda!" • "Stop Lazlo!" / "The Hot Diggity Dog Show" • "Donald's Stinky Day" / "The Hiking Honeybees" • "Racing Rivals" / "The Hapless Helpers" • "The Goofy Race!" / "Cuckoo for Cuckoo Clocks!" • "The Roadsterettes!" / "Oh Happy Day" • "Phantom of the Café" / "Cuckoo in Paris" • "Super-Charged!" / "Super-Charged: Mickey's Monster Rally" • "Super-Charged: Pop Star Helpers" / "The Chip 'N Dale 500" • "Mickey's Ukulele Jam" / "Grandpa vs. Grandpa" • "Goof Mansion" / "A Doozy Night of Mystery" • "Daisy's Photo Finish!" / "Super-Charged: Daisy's Grande Goal" • "Pluto and the Pup" / "Trouble at Floochi's!" • "Goofy's Drive-In" / "The Iron Mouse" • "Mickey's Big Surprise" / "Meet the Beagles!" • "Snow-Go With the Flow" / "Happy Helpers on Ice!" • "Ski Trippin'!" / "My Fair Pete" • "Super-Charged: The Big Cheesy" / "Shenannygans!" • "You Quack Me Up" / "Tree House Trouble" • "Mickey's Spring Grand Prix" / "My Little Daisy"" • "Mickey's Fun-tastical Field Day" / "Clarabelle on the Mooo-ve!" • "Super-Charged: Donald's Roadster Round-Up" / "The Daisy Dance!" • "Super-Charged: Two Close Friends" / "Mr. Bigby's Big Night" • "Goof Quest" / "Llama Drama" • "Hi, Jinx!" / "Pete's Junkyard Helpers" Temporada Tres: "Mickey's Mixed-Up Motor Lab" / "Wishy Washy Helpers" • "One Unicorny Day!" / "The Happy Horse Helpers!" • "Animal Antics" / "Here, Kitty, Kitty, Kitty!" • "Mickey's Monstrous Truck!" / "Minnie's Vacation Home!" • "Mixed-Up for a Day!" / "Princess Clarabelle!" • "A Gollywood Wedding!" / "No Dilly Dally in New Delhi!" • "Mickey's Thanksgiving Family Fun Race!" / "Happy Thanksgiving Helpers!" • "Caution: Kids at Work!" / "The Snoozy Doozy Pet and Breakfast!" • "Where's Mickey?" / "Cuckoo in Hot Dog Hills!" • "Campy Camper Day!" / "Founder's Day Flounder!" • "Goofasaur!" / "Teahouse Helpers" • "Papa Pluto" / "THappy Valentine Helpers" • "Petey O'Pete" / "Daisy Does It!" • "Mickey's New Mouse House" / "Millie and Melody's Sleepover!" • "Old McMickey Had a Farm" / "Happy Lab Helpers" • "Hard Hat Diggity Dog!" / "Hair-Raising Helpers!" • "Donald's Fast Food 500" / "Mini-Helpers" • "Hanami Hijinks!" / "Happy Harajuku Helpers!" • "Mickey's Roommate" / "Minnie's Bow-tel!" • "Sporty Day" / "Go, Chili Dogs!" • "Goofy's Hot Dog Harvest" / "Puppy Birthday to You!" • "Holiday in Hot Dog Hills" / "Happy Kitty Helpers" • "Enough Stuff!" / "The Hippity Hop Horse Show" • "The Mystery of Hot Dog Lake!" / "Phantom Wing" • "Magic Tricked" / "Art From the Heart!" • "Duck, Duck Geese!" / "Shhhhh!" • "Wheelchair Pals" / "Super-Duper-Stitious Day!" • "Goofy and Pete's Wild Ride" / "The Happiest Day of All!" • "All Aboard the Hot Diggity Dog Express!" / "Flea-bee Jeebies!" • "There Goes Our Fun!" / "Don't Wake the Baby!" • "Donald’s Dilemma" / "The Royal-ympics!" • "Dale's New Pal" / "The Cuckoo Turnstyler!" • " • "It's a Hap-Hap-Happy Hot Dog Hills!" / "Happy Friend-iversary" • "Crooner Mickey" / "Once Upon A Lemonade Stand" • "Holi, By Golly!" / "The Pink City!"
