Veralidaine Sarrasri, knowing the animals would help Kel anyway, wanted to increase their knowledge so they would be completely aware when doing so, helping both them and Kel. She was apprehensive about doing so, and only did because she knew that Kel would watch out for them. Duck was one of the animals who received Daine's magical help.
In one instance, when they were expecting an attack, he told Kel that there were 15 of the enemy nearby.
Duck only appears in Lady Knight.