Silver was a rabbit that was an officer of the Sandleford Owsla. According to Bigwig the other Owsla officers teased him for only getting the job because Silver was Threarah's nephew, but Bigwig and Silver would always show them who was weak by fighting them.
Bigwig brought him along on the journey because they were good friends from the Sandleford Owsla. Silver and Bigwig have a sort of partnership because they do everything together, when it comes to scouting and Owsla business. When they had to scout out the area near Warren of Snares or check to see what was making that awful noise near the Watership Down Warren it was the two of them to do it. Silver is also very tough and strong like all the other Owsla officers were. He is a great fighter as shown, when he and Captain Holly went to Efrafa to take the does back to Watership Down, when he came back as the only one who wasn't wounded or ill. Silver is also really good friends with Holly because Holly could tell Silver what he couldn't tell Hazel-rah or even Bigwig. Silver is a really strong rabbit, like Bigwig and Holly, and he is very alert. When he, Holly, Strawberry, and Buckthorn were escaping Efrafa he detected that the Efrafans were still after them. He is loyal and strong in both heart and physical strength. In many ways he may be stronger then Bigwig but does not have the same boldness or confidence as him. This is shown in the book when he says he will go back to Efrafa, as long as he do not have to go in by himself.
In the film, Silver has a role the same size as his book counterpart, appearing as an over-medium sized grey rabbit with a rather slow personality. However, he acts much more like the film counterpart of Hawkbit, sharing his personality and his role in questioning the authority of Hazel.
At first, Silver is just another ordinary rabbit in Sandleford Warren; but shares Hazel's view of the warren's Owsla being too mean. And so, Hazel, Fiver, Bigwig, Blackberry, Dandelion, Pipkin, Violet and himself depart Sandleford Warren. Like a couple others in their group, Silver doesn't entirely trust Hazel and Fiver. Saying "It keeps getting worse and worse wherever we go. Where ARE we going?". After the incident in which Bigwig was caught by a snare, he seems to accept the leadership of Hazel.