Grisha "G." Callen
Grisha Aleksandrovich Nikolaev, better known by his alias Grisha "G." Callen, is a fictional character in the show NCIS: Los Angeles. He is an NCIS Special Agent in Charge, and the senior agent assigned to the Office of Special Projects. Callen is a highly skilled agent with a dark past, and he is often called upon to handle the most dangerous and sensitive cases. He is a master of disguise and has a knack for getting into and out of trouble. Callen is a complex and fascinating character, and he is one of the most popular characters on NCIS: Los Angeles.