Whiff is a grubby green tank engine who collects refuse. His main task is collecting garbage and scrap, which explains his dirty appearance and smell.
Whiff’s has a look and a smell all of his own! He's a cheery, little tank engine with a very special job - he collects rubbish! Whiff doesn't care about his appearance, he only cares that he gets the job done. Whiff loves collecting rubbish and doesn’t notice the turned up noses he passes along the way. 
When Whiff first arrived on Sodor, he told Thomas that getting dirty was fun but when rubbish fell on top of him poor Whiff was leaved underneath it for a whole hour but then Thomas decided to come to his rescue and removed all the rubbish with the help of Rocky the big red crane. When Scruff got trapped under a million rocks whilst trying to befriend Paxton, Thomas, Whiff and all the Narrow Gauge engines were there to help out. But one day, Whiff lost his glasses and the other engines had to help him find them. Whiff is very kind and gentle.
Whiff is cheerful and optimistic. He enjoys his job of collecting garbage. He doesn't seem to care what the other engines think about him: either that or he is oblivious to their opinions. Despite that, he is friendly and always does his job well. He is somewhat naive, as he didn't realise why the other engines tried to avoid him so much. However, in Misty Island Rescue, he is shown to know about Sodor's history, since he knew about the tunnel connecting Misty Island to Sodor.
Whiff is based on the North Eastern Railway X1 Class 2-2-4T No. 66, known as Aerolite. It can be found today at the National Railway Museum in York.
- Keith Wickham (UK; Misty Island Rescue onwards)
- William Hope (US; Misty Island Rescue onwards)
- Whiff is the first and only engine to wear glasses in the television series. However, if Railway Series characters were counted, Whiff would be the second engine. The first being the Ballast Spreader.