|“||Rumblin' and a tumblin'||”|
— Tumbler's Catchphrase
Tumbler is a large cement mixer truck who transports concrete for building sites. He is the loudest machine on Bob's team.
Tumbler is very noisy, and due to his large size he thinks he is strong, brave, and tough. He's prideful and tends to brag about his size. But all and all he's got a gentle side he shows to his friends, particularly Dizzy.
Tumbler is orange-yellow with green stripes. His tyres are black and his bumper, grille mouth and cylinders are silver.
- Season 15 - Tumbler and the Skate Park and Tumbler's Perfect Promenade
- Season 16 - Tumbler and the Ice Rink, Lofty's Banana Tree and Breezy Bristle
- Tumbler is one of the machines who hadn't been seen using a Talkie-Talkie.
- In the UK dub, Tumbler speaks in a heavy Cockney accent. But in the US dub, he speaks in an eastern Bronx accent.
- Tumbler was the largest machine before his size was beaten by Rubble.