Fan Casting The Man-Thing (MCU Film)

There was an accident in the swamp, a man gone missing, that man: Dr. Ted Sallis. Researching and attempted to recreate the Super Soldier formula that created Captain America many years ago, the good doctor finds himself betrayed by the lady he considered his 'partner' to the organization A.I.M. and left for dead in the murky waters. But, afterwards, those who were responsible for his death slowly start to become dead themselves. What is the cause of this... and.. WHAT IS.. THE MAN-THING?