Pum

He was named by Bapap as to identify a certain Grunt Yayap. Because Unggoy are not allowed to have a last name by the Sangheili it is impossible to know exactly who they are just by naming their front name. That's why a famous person in the Unggoy's family and the Unggoy's homeplanet are also named.

Trivia

 * It is possible that the Grunt Yayap named by Bapap is the same Unggoy as the Yayap in Halo: The Flood