Gafinilan-Estrif-Valad was an Andalite warrior who was apparently trapped on Earth during the initial clash between the Yeerks and the Andalites.
Gafinilan avoided actively engaging the Yeerks in combat because he had to take care of his shorm and mate Mertil-Iscar-Elmand, who had an apparent allergy to the morphing technology that left him unable to use it and had lost his tail-blade in the crash. While Gafinilan was able to morph, he suffered from a rare genetic disorder that would eventually kill him, requiring him to take medicine to dull the pain of his illness as he could not overcome it naturally; even if he morphed, his body retained the disease when he returned to normal.
Eventually making a life for himself as Henry McClellan, a professor at a nearby university, Gafinilan attempted to care for Mertil while trying to find a cure for his disease. When Mertil was captured by Visser Three, Visser Three attempted to force Gafinilan to lead the 'Andalite bandits' into a trap in exchange for Mertil- having no use for Mertil or Gafinilan as hosts due to their respective disabilities-, but Gafinilan attempted to use the trap as an opportunity to acquire one of the other Andalites to regain his old strength. However, this plan was ruined with the discovery that Aximili-Esgarrouth-Isthill was the only Andalite in the group, as Ax was so young that it would take too long for his body to grow to a point where it would reach the physical condition that Gafinilan was used to.
Despite his attempted betrayal, the Animorphs helped Gafinilan rescue Mertil, Mertil subsequently assuring them that he would take care of his mate as his condition worsened.
- Though not mentioned directly, Michael Grant released later in a post about Diversity , that Gafinilan and Mertil were in fact a couple.