Brian Flagg was portrayed by Kevin Dillon in the film The Blob. He is one of the protagonists of the 1988 remake of the Blob.
Brian is seen as a Rowdy by the others. He has a motorbike and makes it a hobby to make stunts with it.
One night he discovers The Can Man, when he was attacked by The Blob. He carries him to the hospital with the help of Meghan and her boyfriend. Megan reports later what happened to him and her boyfriend when they were killed by The Blob. Then he, together with Megan, investigate the appearance of The Blob while protecting themselves from it and helplessly seeing it killing townspeople.
When they both go to the place he found The Can Man, they discover the armed government unit and report what happened. Realizing that something is wrong based on his observation their trucks have no marked plates, he escapes, discovers the truth regarding the government appearance and the government conspiracy to catch the Blob, which turns out to be a product of a bio-weapons experiment in space and which the government intends to catch even sacrificing the townspeople, including Megan, on the way too, if necessary, in the name of the Cold War.
He manages to save Megan when they knowingly intend to sacrifice her at one moment and destroys the conspiracy. Later he stops the Blob with her help when they finally realise he can be stopped through coldness while also saving the town. They do this by exploding a truck full of artificial snow he brought to The Blob near it. This explosion releases the snow and causes it to completely freeze The Blob. After that they both embrace in relief.