Bigwig is the tritagonist of Watership Down. He is a strong rabbit known for the tuft of hair on his head from which his Lapine name, Thlayli (literally translating to "fur-head"), is derived. He was part of the Sandleford Owsla with Silver and Captain Holly.

Along with several others, he left with Hazel and Fiver. Hazel hesitated at first to bring him along because of his stubborn nature, thinking Bigwig might be a bully and troublemaker. Luckily, Bigwig proved to be one of the party's most valuable members, though he tends to be quite gruff. Bigwig is the strongest of the Sandleford rabbits and an accomplished fighter. He survives two usually fatal situations, being snared in Cowslip's Warren and a brutal fight with General Woundwort. He is also known to be the bravest of the group.