Walter

Walter is a male Earth pony who appears in the episodes The Cutie Pox and Slice of Life, dressed differently in each, and in the IDW comics, with a speaking role in Ponyville Days. He is unnamed in the show, but he is named variously in merchandise and other media.

Development and design
Walter is one of four ponies based on characters from The Big Lebowski: himself, based on and named after Walter Sobchak (played by John Goodman); Jeff Letrotski, based on and named after Jeff "The Dude" Lebowski; Jesús Pezuña, based on and named after Jesus Quintana; and another Earth pony stallion, based on Theodore Donald "Donny" Kerabatsos. He shares his coat and mane colors with Dr. Hooves, Crescent Moon, and Dance Fever and his facial hair style with Unnamed Earth Stallion #3 and "Nightjar".

Meghan McCarthy stated on the homage to The Big Lebowski and easter eggs in the show, "Very rarely are those things written into the script, but then when it goes to Studio B and the board artists and Jayson Thiessen, supervising director, I think they have a lot of fun. They have to populate this world with these background ponies and they’re like ‘oh, they’re at a bowling alley, eh?’" A fan's thought that the bowler stallions' inclusion in The Cutie Pox "was just the animators amusing themselves, rather than a sop to the adult audience" has been agreed to by Jayson Thiessen. Tim Stuby "had nothing to do with Lebowski" ponies.

Season two
Walter appears alongside Jeff Letrotski and another Earth pony stallion at the beginning of The Cutie Pox. At the Ponyville bowling alley, he dodges Scootaloo's bowling ball as it careens across the building.

Season five
In Slice of Life, Walter appears with Jeff Letrotski and "Theodore Donald "Donny" Kerabatsos" at the Ponyville bowling alley. Dr. Hooves joins their bowling team in a championship game; when Dr. Hooves gets a gutter ball, Walter stands up and grunts in anger. Walter also appears at Cranky Doodle Donkey and Matilda's wedding holding a coffee can.

IDW comics
Walter appears on the IDW comics' regular cover and, with several lines of dialogue, pages 6, 17, and 21 and  pages 6 and 20.

My Little Pony (mobile game)
In Gameloft's mobile game, Walter is available as a playable character; he is referred to simply as "Bowling Pony" in gameplay and promotional material, but he is called "Pony_Walter" in the game's internal code. His in-game description states he is "An Earth pony who who commonly frequents the bowling alley, although he doesn't roll on Saturdays."

Merchandise
Walter appears on the Season 2 poster/DVD set packaging/T-shirt/WeLoveFine.com iPhone case, is shown in an image from The Cutie Pox on the back of Enterplay trading card series 2 #60 card "The Three Strikes?", appears on the WeLoveFine T-shirts "My Little Urban Achievers" and "Walter Pony".

Quotes
"I don't think there's a bowling alley in Sweet Apples [sic] Acres, is there?"

"Are you thinking what I'm thinking?"

"Bowling tournament? Count me in!"