Spot, Rover and Fido are the three main Diamond Dogs and the main antagonists of the episode "A Dog and Pony Show." They wear jackets and diamond-studded collars, while the rest of the Diamond Dogs wear metal armor and carry lances. They alternate between walking on their hind legs and all fours, their elongated forelegs giving them a gorilla-like appearance. They also have short and stubby spiked tails. They are also very stupid which make them the easiest antagonists for Rarity to outsmart on her own. Fido is the blue bulky one with the grey jacket; he is voiced by Garry Chalk, Spot, the small bulldogish one is voiced by Lee Tockar and Rover, the grey one and the leader is voiced by Scott McNeil.
In the episode, the Diamond Dogs secretly watch Rarity and Spike as they collect gems, initially thinking Spike is the gem finder, before realizing that Rarity is using her magic to find them. They then make themselves known and tell Rarity they hunt for gems, and will hunt for her since she can find the gems. They have a tussle with Rarity and Spike but manage to abduct Rarity into their extensive system of underground mines.
They attempt to force Rarity to find gems for them, but Rarity puts on a complaining and whining act, tricking them into doing all the work while she relaxes. When Rover gets wise to this, he forces Rarity to pull the gem cart, calling her a mule. In response, Rarity acts hurt, crying loudly about being compared to an "old, ugly mule." By the time Rarity's friends arrive to save her, the Diamond Dogs are begging for Rarity to leave, even letting her take all their gems with her.
They are set to debut in the RMCF story where their role is the same, but they abduct Trixie Tang after witnessing her power that was given to her her by Tricia temporarily. Luckily, like Rarity, Trixie manages to outsmart them.
- Their voices and some of their mannerisms appear to be based off and inspired by the Lord of the Rings character Gollum.
- Theri names wren't mentioned in the episode, but were confirmed in the script.
- Their species are named after the David Bowie song
- RMCF: A Dog and Rookie Show(Debut)