Green ninja

The image provided appears to be a blurry photograph focusing on light and shadows within an interior space, likely a video or a snapshot from one, but it does not contain a "green ninja".
The term "Green Ninja" most commonly refers to Lloyd Garmadon, the main protagonist and leader of the Ninja team in the popular animated series Ninjago: Masters of Spinjitzu.
Key aspects of the character include:
Role: Lloyd is the prophesied Green Ninja, destined to save the world from the Dark Lord (who is revealed to be his own father, Garmadon).
Powers: He is the Elemental Master of Energy, which allows him to project green energy beams, create shields, and summon an energy dragon.
Popularity: The character is consistently popular and has appeared in numerous Ninjago TV series, a feature film, and many associated LEGO sets and merchandise.
Other "green ninja" references identified in search results include the Pokémon Greninja, various ninja-themed costumes and toys, and a science education curriculum called "Green Ninja".