He first started out as a marvel at a side show, whom was able to hold two bigfoot trucks with his bare hands. Fred had lost his balance while standing ontop of the trucks and fell down and was laughed at.
His most vulnerable weakness is the mockery of others.
He then joined the BRotherhood. At his first day at Bayville HIgh, Fred is made a mockery by Duncan Matthews and was about to thrash him until Jean Grey intervene.
Helping him with his schedule, Fred had found his true friend and girlfriend. Of course, she didn't really like as in boy/girlfriend status, but as a friend. Wanting her to go out with him, she forced her to have dinner with him.
Rescuing her, the X-MEN could hardly do anything save her, except for Rogue. She was able to blast him into a garbage dump.
He returned, unharmed, and roamed the school as a bully.
Years in the future, the Blob and the Brotherhood will be known as Freedom Force, a mutant team that works for S.H.I.E.L.D..