Jerso

Jerso (ジェルソ) (also spelled Jelso) is a military operative under the command of Solf J. Kimblee. He was used as a test subject in military experiments and is now a human chimera capable of transforming into a strange, toad-like creature. He is partnered with Zampano.

Part in the story
While being part of the military, Jerso and his partner Zampano were Kimblee's body guards. They confront Scar and are easily defeated by him and the Elric Brothers. Before Major Miles has a chance to execute them though, Alphonse convinces them to come with them on the promise that they may be able to get back their original bodies. They escape in the old mine shaft with Al, Scar, Dr. Marcoh, May Chan, and Yoki.

While in a small Ishvalan refugee camp, the group confronts Envy after Zampano tips him off to their location. Zampano actually tricks Envy into coming there to fight them, and plays a part in battle against the homunculus. May's long range alchemy, his and Zampano's attacks, and Marcoh's Philosopher's Stone are what ultimately defeats Envy.

After May is supposed to return to Xing with a weakened Envy, the rest of the group travels toward Reole where Zampano, Jerso, and Yoki would help with the rebuilding. After the time-skip, they head towards Central and meet up with Edward, Darius, Heinkel, Lan Fan, Fu and Hohenheim. They aid in Mustang's invasion of Central, infiltrating the bowels of the city and capturing the Gold-Toothed Doctor with his spit. He is then wounded by Pride and drops the Doctor to the ground as he falls. He is incapacitated for the rest of the battle due to his injuries. He is last seen with Zampano in a café, discussing different methods to get their bodies back, and are about to set off to Xing with Alphonse as his bodyguards.

Abilities
Jerso is a human based chimera and can transform into a large toad-like monster. While in this form, he can spit an extremely sticky saliva that can immobilize his targets and can also move quite fast for his bulbous size.

Trivia

 * The names of Jerso and his companion Zampano may have been derived from that of the two main characters, Gelsomina and Zampano, in the 1954 Italian film La Strada, directed by Federico Fellini.