Ninja Turtles are rad! I had to have a section on these guys, I grew up on them! More to come, I'm a busy ninja.

TMNT: The Animated Series Origin

Hamato Yoshi was the leader of a branch of the Foot Clan in Osaka, Japan.  On the night of the Master of the Foot Clan's visit, Saki pinned Yoshi's robe to the wall with a dagger.  When this prevented Yoshi to bow to the Master, the Master's guards were infuriated.  Yoshi then pulled the dagger from behind him, and made it look as if he was planning on killing the Master.  The guards got Yoshi and asked the Master what to do with him.  Master replied, "Throw the bum out!"  So, he had to flee to the land of oppurtunity:  USA.  Forced to live in poverty, Yoshi moved to the warmth of the sewers.  After spending time there, and making friends with the rats, Yoshi decided that the sewers were the best place to be.  Meanwhile, Saki gained power in the Foot, and began teaching them to be thieves.  They, too, moved to the USA, and Saki began calling himself The Shredder.  Allying himself with thugs, and an alien warlord known as Krang, Shredder gained the brute strength and technological equipment to do his bidding.  Somehow, he found out that Yoshi still lived and thought he might pose a threat to his plans for world domination.  So, he gained access to Krang's latest invention:  Mutagen.  It's radioactive properties were meant to kill Yoshi.  It happened that the day the Shredder dumped the gel into the sewer, four tiny turtles were dropped by a clumsy kid down a storm drain.  Yoshi, and his pet rat heard the shattering glass of the terrerium, and went to investigate.  They found the turtles writhing in a glowing ooze.  Yoshi picked them up, cleaned them off and set them down.  Immediately, they transformed into humanoid creatures, and Yoshi transformed into a rodent-like creature.  Accepting their new forms, Yoshi began teaching the Turtles all he knew.  He taught them to read, write, and fight the forces of evil.  During a training session, Yoshi completely destroyed a wooden plank.  This earned him the name Splinter.  Splinter taught the turtles to respect everyone, and everything including the earth.  One night, a television field reporter by the name of April O'Neil was reporting at a crime scene.  The place had been hit by ninja thieves who stole computer hardware.  She decided to do some investigating.  Two thugs came out of the shadows announcing that "the Boss"  wanted them to make sure she stuck to reporting fashion shows.  The resourceful reporter threw her camera at one of the thugs, and ran for her life, seeking refuge in the sewer.  The thugs were in persuit.  A chase beneath the streets followed, and April ran head first into a brick wall.  When all seemed dark for her, four figures from the shadows emerged.  They took on the thugs, and sent them running.  April awoke to a fuzzy hand offering her "Some hot tea?"  She freaked and fainted again.  When she was revived for the second time, she met her rescuers.  Four huge turtles, and a therapeutic rat-man.  They told their story, as I have just told you.  April thought that they may be the ninja thieves, but was soon convinced the Rennaisance named teenage turtles were there to protect her, the city, and the world.