CW's 'The Flash' has released a new trailer for their upcoming episode, "Grodd Lives." This will serve to fully introduce one of the greatest threats in 'The Flash' universe, and fans of the comic books should recognize him as such.

The first season has been steadily winding down and is faced with three episodes left. Team Flash have all realized that Harrison Wells is in fact Eobard Thawne, the Reverse Flash, and will not only have to fight for their lives, but the truth to what happens to Barry and him in the future.

Gorilla Grodd has been teased various times throughout the season as this mutated beast that lives underground. In this new promo we get to see him face off with The Flash, as he has been established as an ally of Harrison Wells.

Iris West has also been recently dragged into things when Barry's identity as The Flash becomes revealed to her.

Here's a full synopsis of the episode:

"'Grodd Lives' - Barry (Grant Gustin) must deal with the Reverse Flash's (Tom Cavanagh) latest threat to a member of the group. To make matter worse, Dr. Wells unleashes Grodd on the city in order to distract Barry and the team. Joe (Jesse L. Martin), Barry and Cisco (Carlos Valdes) head down into the sewers to catch Grodd but the gorilla quickly gets the upper hand after he kidnaps Joe. Iris (Candice Patton) and Barry have a heart to heart talk. Dermott Downs directed the episode written by Grainne Godfree & Kai Yu Wu."

'The Flash' airs on Tuesdays 8/7c on the CW.