Diamond Tiara is a snobby, conceited school-age Earth pony and a minor antagonist who first appears in Call of the Cutie. She and Silver Spoon are classmates of the Cutie Mark Crusaders. She is also the daughter of Filthy Rich, a successfull businessman who is friends with Granny Smith and the owner of his own company, Rich's Barnyard Bargains. Due to her cruel behavior, she is usally punished by him, for example in the ending of the "MLP: FIM" episode "Family Appreciation Day", being forced to wear a pair of bunny ears and hop around watering cans while singing the Alphabet song.
- Diamond Tiara will become the bully of Winnie the Pooh in Pooh's Adventures of My Little Pony Friendship is Magic.
- Diamond Tiara will become a bully but also an nuisance, of the FT Squad in The FT Squad's Adventures in My Little Pony: Friendship is Magic.
- Diamond Tiara along with Silver Spoon are also best friends with Arry and Bert.
- While during Filthy Rich's speech to Cheerilee's class in his debut episode, Diamond Tiara is alert and attentive during his speech, while most of the other students are all bored and are all taking naps. It might be hinted that she has a huge crush on him, making them both a couple.
- Also, in that same episode, Diamond Tiara suffering punishments by Filthy Rich somewhat looks exactly simillar to Cera suffering horrible punishments and forbidden to do things by her own, strict and cruel father, Daddy Topps, from "The Land Before Time", a film series known for having musical numbers.