Oliver is a wise old excavator who carries out demolition and digging work. He is capable of switching between different tools, including his usual bucket, a chisel for digging, a scissor claw, and a wrecking ball for demolition.
Oliver was first seen clearing room for railway lines at a quarry. The foreman called him to move some rock, but Jack wanted to move it himself, causing him to topple over on a hill. Jack learned from this, and allowed Oliver to do his jobs. A while later, he was digging foundations when he discovered some dinosaur bones, and appeared on the front page of Sodor Times.
Oliver is wise and kind and keeps an eye on the other members of the Pack. He is good-mannered and hard-working and never complains about his work or gets impatient. He has the power and precision capability of moving and digging tons of earth in a single day. Oliver is kind and wise and watches over all the machines who work for the pack; because of this he can always be relied upon by Miss Jenny as a team leader.
Oliver is painted brown with a pale green panel on his back and his number painted on him in red. Oliver has the cap rim of a builder's hat between his forehead and cab windows.
- Season 2 - Races and Alfie's Lucky Day
- Season 3 - Jack and Alfie Swap
- Season 4 - Serious Samson and George and Buster
- Season 5 - Nigel, Bumble Bucket, and Stanley's Branch Line (mentioned)
- Season 8 - Mucking Mud
- An early concept design for Oliver reveals his name was originally meant to be Buster.