Long ago, a tortoise beat a hare in a footrace. It's a tale we all know. The tortoise was cheered by all and went on to live a happy life. The hare... well, things didn't go so well for him. This is his story.
Ridiculed and shamed, his life in shambles, the hare was driven to isolation, to the musty dark of the Fermented Forest! There he became crazed with self hatred, and obsessed with REVENGE. Living on a diet of dusty, odd mushrooms, his mind was warped even further, while his body never aged. He worked out constantly, got super jacked, ultra strong. His legs could crush tree trunks, he could hear a leaf swooshing in the breeze, became ultra alert. He trained ferociously, studying every type of fighting method ever invented, and even created a few new ones. He began to pray to the moon, to Firth and to The Black Rabbit of Inlé. Soon his prayers were answered.
A shadowy figure with a shredded cloak came to visit him one day and showed him pictures of 4 turtles living far away. This figure said that they were the Sons of the Tortoise that beat him.
The hare had become The Black Rabbit, an ancient fighting force from another time, and now it knew what he had to do.
KILL the TURTLES!
I entered this character into a contest a couple days ago on CGHUB about fictional Teenage Mutant Ninja Turtles Villains. Username - LandofMcQuade