Sebastian

Sebastian is the name of Radagast's hedgehog. 
Radagast discovers a sickness falling upon Greenwood the Great while just outside his home one day, seeing several plants and animals that are dead or dying -- Sebastian being one of the latter. He brings the hedgehog back in an attempt to revive him, but none of his home remedies work. In the process, several large spiders begin to descend on Rhosgobel. Radagast decides to use his magic on Sebastian, and when he finishes his incantation of the spell, the spiders return to the place from whence they came. Meanwhile, the spell has cured Sebastian, and he appears completely back to normal.