See how often they participate in the script: HERE.
Character Story: Boar-like creatures found throughout the game. They are usually ridden by Bulblins. Lord Bullbo is a particularly large and armored Bullbo which belongs to Lord Bulblin.
Race Story: Animals appear all throughout Hyrule and are often often helpful in their own ways, either directly or through subtle advice. Link can talk to them when he is in his wolf form.