Botarus was a large male bittern. He was a friend of Madd. He had found her wounded in her head, and nursed her back to health. Though he appeared quite sane, Botarus claimed that he was sometimes as crazy as his friend, and that was how he was able to put up with her. They also shared an intense dislike of vermin. At first Botarus suspected Tagg of being a vermin, but quickly changed his mind when he realized Tagg was an otter. However, Madd refused to believe Tagg wasn't vermin, so Botarus led Tagg to safety away from her.
"Botarus" probably comes from the Eurasian Bittern's Latin name, Botaurus stellaris.