Chronicles of a Lizard Nobody - Patrick Ness - Bog

"When Principal Wombat makes monitor lizards Zeke, Daniel, and Alicia hall monitors, Zeke gives up on popularity at his new school. Brought in as part of a district blending program, the monitor lizards were mostly ignored before. Reptiles aren't bullied any more than other students, but they do stick out among zebras, ostriches, and elk. Why would Principal Wombat make them hall monitors? Alicia explains that it's because mammals are afraid of being yelled (hissed) at by reptiles. The principal's just a good general, deploying her resources. Zeke balks--until he gets on the wrong side of Pelicarnassus"--