- "His name's Merlin. Hopefully he'll be a bit of a magician"
- — Ty Borden
Merlin is an orphaned foal found by Scott and given to Kit Bailey when her horse Daisy's foal dies.
When Daisy rejects Merlin, Scott brings him to Heartland in the hope that Amy and Ty can look after him until he finds a new home for him. Amy and Ty take turns waking up through the night to feed Merlin, when Amy wakes up she goes to the barn and finds Ty still sitting with Merlin, he tells her that he couldn't leave because he wouldn't go back to sleep. In the morning, Ty is with Merlin again, Amy tells him that since he's with him he could start getting him used to a halter but he doesn't want to because he's so young but Amy tells him he needs to because otherwise he'll grow up with behaviour problems. Amy and Ty are with Merlin in his stall, she convinces Ty to leave him but when he starts "crying" he turns on his heels and sits with him. The next day, Amy tries to teach Merlin to drink from a bucket and Ty tries to take a more gentle approach whereas Amy tries to teach him boundaries, causing issues between the pair. After they learn that Scott has found Merlin a new home Ty starts getting him used to other horses and he doesn't look back. (Growing Pains)