Sollertree ("Soll"), formerly known as "Skyspike," was a hedgehog recluse who was a good friend of the otter Goodwife Brimm. He was the husband of Beechtip and fathered a daughter called Nettlebud. His wife was killed and his daughter kidnapped in a vermin raid. Sometime after this, he renamed himself "Sollertree" (from the word "solitary") and settled down growing nuts and kept a pet frog named Croikle, of which he was quite fond. He re-built his home again after looking for his daughter for many seasons. He aided Song, Dann, Burble, and Dippler; and later reunited with his long-lost daughter.