Brock

Summary
Brock is the Blob's physical form, taking along with it a somewhat distinct consciousness different from John. Brock is De Blob's spiritual body taken over by a iron golem, giving him endless power and being one of the most powerful beings within the Monky Cinematic Universe.

Death
Brock was killed by Gavin, who at the time was taken over by the man. By further investigation, The Man was revealed as John in disguise, using his powers to influence those close to Brock to kill him. John had decided he needed his Blob's power once more, so he needed it to return to the spiritual realm to fuse with John.