Timmy is one of the recurring characters in Shaun the Sheep, and he’s a young lamb, not just an ordinary sheep. While the term “fat” might be an exaggeration, Timmy is definitely round and a little chubby compared to some of the other sheep on the farm, which might be why you associate him with that description.
Timmy is often portrayed as being quite mischievous, curious, and at times, a bit of a handful for Shaun. Though he’s just a little lamb, his antics are often at the heart of many of the more humorous or chaotic moments in the show. He also has a distinctive cry that is almost like a babyish “baa” (since he’s young), which adds to his charm.
He sometimes gets into trouble because of his innocent and naive nature, but other times, he can be surprisingly clever or helpful. Timmy is quite a lovable character and often serves as a foil to Shaun’s more responsible and leadership qualities. As the show progresses, Timmy grows up a bit, but he remains a fun, energetic character in the series.
In the spin-off Timmy Time, Timmy is the central character, and the show focuses on his adventures and experiences as a little lamb, making it more focused on his character development in his early days on the farm.