Donatello or Donnie is one of the main protagonists of the Teenage Mutant Ninja Turtles 2012 television series. He is the adoptive son of Splinter, and the biological brother of Leonardo, Raphael, and Michelangelo. He is also the younger adoptive brother of Karai. He is the team's scientist, mechanist, inventor and weaponry who is in charge of the design and manufacture of all the tools, gadgets, armor, vehicles and weapons in Turtles' arsenal and is also a gifted hacker. Wearing a purple mask, he fights with a bō (rokushakubo) which also converts to a naginata (a Japanese halberd) via a switchblade inside one end of the wooden staff. In this version, Donnie has a huge crush on April O'Neil (who is also in teenage years in this adaptation), and later develops a rivalry with Casey Jones because of it.
In the 2012 series, Donatello is still the brains of the team, but the results of that role as a teenager are played up considerably. He’s constantly being teased by his brothers (especially Raphael), his social skills are less than adequate, and his feelings for April are unnoticed by the girl because he just can’t find the words to express his feelings. However, his ninja skills gain a boost as well. His bō staff now transforms into a naginata, giving him mastery over yet another skill of ninjutsu.
Despite being book smart, he sometimes does not understand and/or has a hard time grasping the lectures of Master Splinter. His character design was also updated, giving him a gap in his teeth and a taller, leaner appearance with a skinny body shape than his brothers.