"Ned's Life as a Dog" is an episode of Nightmare Ned.
One day at school, two bullies named Conrad and Vernon trick Ned into eating dog food. This gets Ned wheezy and worried, so later that night Ned has a nightmare in which he undergoes a painful transformation and becomes a cute little dog.
Ned Needlemeyer (also as dog)
Conrad (also as cat)
Vernon (also as cat)
3 fleas (red,blue,and green)