Bulk

Bulk is Hanson Harold, a genius molecular scientist who ran extensive experiments on energy manipulation at the atomic level. When an IRS auditor showed up at his lab to check on his funding sources ('cause they really were pretty cagey.  srsly.), he raced toward the accounting office to set fire to it to cover his tracks. On his way he bumped the table in the break room that held the microwave, and when it landed on the floor it emitted a pulse of energy that reacted with an experiment on the other side of the room (he often did science in the lunchroom). The result was an explosion that leveled the building, irradiated the surrounding area, and caused a number of headaches for the local EPA agents. However, Harold survived, his molecules increasing rapidly in size, allowing his body to overcome the release of energies. The ratiation had somehow given him the power to manipulate sizes of molecules, and he became Bulk!

Unfortunately for Bulk, the IRS auditor also survived, and the explosion gave him the power to see through people's wallets. He became the supervillain Enrolled Agent and is able to levy Hanson Harold's bank accounts whenever he opens them.