Spike is a purple and green baby dragon. He is Twilight Sparkle's friend and assistant. His ability to magically deliver scrolls to and from Princess Celestia with his green fire-breath is featured in many episodes, as is his crush on Rarity. Spike will make his first appearance in Thomas and Twilight Sparkle meets Dumbo and at the end of the film Twilight would like him to join the team.
- In Thomas and Twilight Sparkle meets Dumbo, Spike joins Twilight, Thomas and their friends on their adventures.
- Spike met the FT Squad in The FT Squad's Adventures in My Little Pony: Friendship is Magic.
- Spike guest starred in The FT Squad Meets the Hunchback of Notre Dame, and later will in The FT Squad's Adventures with the Winx Club.
- Spike will make occassional guest appearances in The FT Squad's Adventures With Phineas and Ferb, and will officially guest star in The FT Squad's Adventures With Phineas and Ferb: Summer Belongs to You.
- Spike is best friends with Bertie and Luke.
- He also owns a hoverboard in Thomas and Twilight Sparkle's Adventures Chronicles.
- He is very great friends with Soos and Mac.
- He is the "semi-biological" son of Barney the Dinosaur, mainly because he found his egg and decided to hatch it himself, like Horton did in his first book, Horton Hatches the Egg. This possibly explains Spike's purple skin and green stomach, and other things about him. He's also Bloodgood's step-son, and he calls Louis and Ronald McDonald his 'uncles'.
- Twilight, Sunset and Trixie transformed Spike into a Unicorn in the near end of The Magic of Friendship.