History
Theodore Sallis developed the SO-2 Serum that turned him into a Man-Thing.[1] This side-effect, in addition to the connection of the Nexus of All Realities, were later attributed to mystical enhancements to the serum that Dr. Salis bargained for from the demonic sorcerer and ruler of Limbo, Belasco.[2]
Properties
The SO-2 Serum gave its user immunity to all known toxic biochemicals. However, it was declared unusable when it was discovered that it had a side-effect: turning its users into monsters.[3]