The Informant is one of the most enduring and beloved characters in the Marvel Cinematic Universe, and the one character to appear throughout most movies and TV shows set in the MCU.
He is a Watcher, an ancient god-like alien being. His role is to chronicle the history of the MCU to his fellow Watchers, something that his ability to exist across space and time allows him to do.
He is played by the late Stan Lee, with the character being somewhat based on him.
Due to Lee's death, it is presumed that the Informant is likewise deceased, with Avengers: Endgame being the last MCU production to feature the character.
The Informant is show to be kind, caring, gentle and wise, even if a little goofy.