Mysterio

Mysterio (real name Quentin Beck) is a Marvel Comics supervillain who appears in the Marvel Cinematic Universe film Spider-Man: Far From Home. Mysterio was created by Stan Lee and Steve Ditko.

Ultimate Spider-Man
Mysterio appears in the Ultimate Spider-Man episode "The Moon Knight Before Christmas" voiced by Paul Scheer. Quentin Beck is portrayed as an old enemy of Spider-Man and former stage magician who is presumed dead after an encounter with Spider-Man when he fell off the Brooklyn Bridge. Spider-Man dove into the river and only found Mysterio's helmet at the bottom of the river while his body is nowhere to be found. Since that incident, Spider-Man gave his helmet to Doctor Strange for safekeeping at the Sanctorum. Following his death, his daughter Frances Beck (voiced by Mary Kate Wiles) uses his helmet in an attempt to exact revenge on Spider-Man as a female Mysterio only to discover that Quentin Beck's soul is trapped within the helmet. Recalling Doctor Strange's saying "The Enemy of the Enemy" is my friend, Spider-Man casts the spell that would enable Frances' pursuer Moon Knight to enter when it comes to Mysterio summoning evil elves, giant gingerbread men, snow monsters created from snowmen, and animated toys. Using a specific wand that the Moon told him to wield, he stabs the helmet with the wand. Spider-Man pretends to follow the Moon by telling Moon Knight to free Frances from the helmet's control. After ending up inside the helmet where he sees Quentin in the helmet as a result of a deal with Dormammu. As Quentin states that his soul is lost, Spider-Man persuades Quentin not to give up. As a result, Quentin Beck, Frances Beck, and Spider-Man return to reality. Quentin and Frances later attend a dinner with Aunt May alongside Spider-Man and Moon Knight.

Spider-Man: Far From Home
Mysterio is the main antagonist of Spider-Man: Far From Home. A former Stark Industries employee, Quentin Beck was the inventor of B.A.R.F., a holographic system that made use of illusions. However, Tony Stark fired Beck for being unstable. After Stark's death during the events of Avengers: Endgame, Beck took it upon himself to seek revenge on Stark's legacy.

With the help of a team of former Stark employees, Beck creates four cybernetic monsters known as the Elementals and takes on the identity of a tragic warrior from Earth-833, an alternate Earth that was ravaged by the Elementals. He unleashes the Elementals upon the world, pretending to defeat them to gain public approval. He first "defeats" Sandman in Mexico, getting the attention of "Nick Fury," and Cyclone in Morocco.

In Venice, Beck first encounters Peter Parker while defeating Hydro-Man. Beck later officially meets Parker on a secret mission, explaining his fabricated story, and gets Parker's help in "defeating" Molten Man. Though Parker refuses, Fury sends Parker and his school to Prague, where Molten Man resides. After a brief bonding moment, Parker helps Beck "defeat" Molten Man, and passes on Stark's sunglasses to Beck, believing he deserves it. Unknown to Parker, Beck has been seeking control of Stark's legacy. Parker eventually realizes that Beck has been deceiving him, and goes to warn Fury of Beck in Berlin. But "Fury" turns out to be an illusion of Beck's, and Beck traps Parker in a series of illusions before making a getaway.

Beck, having learned of Parker's classmates who were in on his secret, discretely sends them to London, where he plans on using an illusion of the fused Elementals to kill them. But Spider-Man, having broken free, intercepts Beck and eventually subdues him at the seeming cost of Beck's life. However, before his assumed demise, Beck sends altered footage accusing Spider-Man of the attacks, and exposes Spider-Man's secret identity to the world.