|For other uses, see Aaron (disambiguation).|
Aaron is a green tank engine who works on the Earl's Estate.
Later, Aaron was sent to take freight cars of garbage to Whiff's Waste Dump. However, he tried to avoid other engines because he thought they'd all tease him for his unique design. Because of this, he ended up being late to the Waste Dump. Once he got to the Waste Dump, he quickly became friends with both Whiff and Scruff.
Then, Aaron, along with his best friend, Theo were sent to help Hurricane and Frankie at the Mainland Steelworks. Aaron and Hurricane quickly became friends due to the two engines being the same design, just with different amounts of wheels.
Aaron is very shy. He is very worried whether other engines will like him or not. Once he overcomes this, however, he is extremely friendly.
Aaron is based on the GER Class A55 "Decapod". Originally, unlike his basis, Aaron had a 0-12-0 wheel arrangement. However, in the Friends Around the World miniseries, Aaron was redesigned with the accurate 0-10-0 wheel arrangement. Hurricane is also a member of this class.
Aaron is painted lime green with purple lining. Originally, he had the number "7501" written on his cab in purple. However, in the Friends Around the World miniseries, Aaron was redesigned without his number, as well as with purple wheels and bufferbeams.