Merlin is an experimental tender engine who believes he has the power to turn invisible and has three funnels.
Biography[]
Thomas & Friends[]
When Thomas travelled to the Mainland, he befriended the experimental engines: Merlin, Theo and Lexi. Merlin sails through life, full of confidence, believing that he has the ability to become invisible. Helping to hide Thomas from Frankie and Hurricane, he promised to help him find his way back to Sodor. Later, Merlin, along with the other experimental engines, helped Thomas rescue James, who had been trapped in the Steelworks.
Afterwards, Merlin offered to stay at the Steelworks to help Frankie and Hurricane and helped Thomas to convince the other experimental engines, Theo and Lexi, to do the same.
When he first came to Sodor, he showed everyone he can become invisible, except Percy, who was upset he did not get to see him. When Percy heard an unfamiliar whistle in the distance but could not see who it belonged to, he assumed it was Merlin, and rushed off to tell Thomas. However, the "invisible engine" turned out to be Trevor.