He comes across as very shy, but when the conversation turns to "shop", Wellington becomes very talkative (asking him the time, for example, would result in a very detailed account of how a clock or a watch is made!) When talking technical, Wellington is prone to using 7 words when one will do and littering his speech with pseudo-scientific language.
Tobermory appreciates Wellington's interest in inventing and has taken him under his wing to try to teach him all he knows. He also tries to encourage Wellington that it's also important sometimes to stop working and have fun.
Because Wellington can get so focused on what he's doing, he has a tendency to be rather absent-minded. The other wombles tease him about this. It isn't uncommon for him to forget an important message, his birthday, or the key safety features he was supposed to include on his latest contraption.
In Series 1 and 2, Wellington wore a blue and black cap with a Womble "W" and black glasses. In Series 3, 4 and 5 (currently), he wears a blue and black cap with a Womble "W", black glasses and a light blue polo shirt with a Womble "W" on it. He found his name when he pointed to New Zealand.