Grodd

Grodd is a gorilla that was experimented on in S.T.A.R. Labs.

Test subject
Five years before the particle accelerator accident Grodd was kept as a test subject in S.T.A.R. Labs. He was scheduled to be part of enhanced gene therapy experiments conducted by Harrison Wells and Wade Eiling, the latter of whom wanted to explore the possibilities of mind control. However once Wells discovered Eiling's inhumane methods he shut down the program but decided on other plans for him.

After the S.T.A.R. Labs accident
After the particle accelerator accident, Grodd's cage was seen to have been destroyed and Grodd escaped. He took up residence in a sewer and began carving his own name in to a wall repeatedly. He was encountered by workmen, who attempted to run but were attacked by Grodd.