Big Mickey first speaks in the episode Munitions, he loads the naval tramper Kraka-Toa with explosives. Later, a fire causes his dock to collapse and he sinks (in the TV version, it is said that he is saved by landing in shallow water). Later, in the episode High Tide, he loaded steel for the Z-Stacks and the Star Fleet.
Big Mickey is known to be supportive towards the Star Fleet, as he roots for them in their competition against the Z-Stacks for the steel contract and according to Zorran, he is clearly his own boss as he noted that: "Nobody tells Big Mickey what to do!"
After the show's conclusion, Big Mickey was recycled as a background prop for Brendam Docks in "Thomas & Friends". His most notable role was in Edward's Brass Band, where he accidentally knocked Edward off the track while unloading a boiler from a ship, though he was not referred to by name.
Like the other former TUGS characters and props, Big Mickey was also carried over to the new CGI series.
In "New Crane on the Dock" from the twenty-first season of Thomas & Friends, Big Mickey gained a face and the ability to speak. Upon speaking up towards the end of the episode, he was thrown off by everyone staring at him, apparently due to the fact that no one on Sodor had realized he was sentient. Cranky asks him why he has not said a single word up until this point, to which Big Mickey responds with the fact that Cranky has never said a single word to him either.
Big Mickey is based on a 350-ton Hammerhead crane. He most strongly resembles the US Navy's "League Island Crane" built in 1919 by the McMyler-Interstate Company for the Philadelphia Naval Shipyard. Weighing 3,500 tons, it was the world's largest crane at the time.
- Timothy Bateson (TUGS)
- Rob Rackstraw (Thomas & Friends)
- Masaaki Tsukada (Japan; High Tide)
- Tarô Arakawa (Japan; Munitions)
- Elise Langenoja (Finland)
- Pauli Virta (Finland; one line in Munitions)
- Sunshine (cameo)
- Pirate (cameo)
- Regatta (cameo)
- Warrior (cameo)
- High Tide
- Quarantine (cameo)
- Ghosts (cameo)
- Jinxed (cameo)
- High Winds (cameo)
- Big Mickey was also shifted to Lucky's Yard.
- His model was recycled and used in Thomas & Friends, beginning in its third season episode "Diesel Does It Again". Out of all the Tugs characters, he has the longest post-Tugs lifespan, along with the S.S. Vienna and the other dockyard cranes some of which are on are on display at Drayton Manor, England, where some of the Thomas the Tank Engine and Friends TV models are now and currently reside.
- It is currently unknown where Big Mickey's model is now due to the fact that Thomas and Friends changed its format from their model version into a CGI version.
- Throughout Thomas & Friends, Big Mickey's model underwent several changes:
- He was repainted a warmer shade of grey.
- His megaphone was removed.
- in Season 5 His top railing became thinner and His walkway became more detailed.
- in Season 6 He had riveted steel sides, His hoist end became covered, His wheelhouse walkway became square and He gained a new base.
- in Season 21, he gained a face and is referred to by name.
- In the Finnish version, Big Mickey is called Iso Mikko.