Ninjago and TMNT(rather the 2012 version cause that's the one I know) seem like almost rip offs of each other. Not really but if you think about it, they're really similar.

First: The characters
Leo- Kai(or Cole)
Raph- Cole(or Kai)
Donnie- Zane
Mikey- Jay
April- Nya
Casey- Lloyd? (Idk)
Splinter- Sensei Wu
Tang Chen- Misako
Shredder- Garmadon (or any Bad Guy)
Karai- Lloyd (IN A SENSE! You'll see what I'm getting at in a minute.) and Skylor

Now for some parts that relate..

-Karai's transformation- Bad to Good and Human to Mutant
Lloyd was turned good to bad and was turn from young to older
Also with Skylor defending herself against her father in Season 4 and Karai did the same

-Donnie, April, and Casey love triangle
Nya, Jay, and Cole were in a love triangle in season 3

-Shredder, Splinter, and Tang Chen past love triangle
Wu, Garmadon, and Misako had a love triangle in the past

There is so much more!! Vote if you agree and comment on if you can spot any more similarities between the shows! Thanks hope you enjoy!