'The Flash' Surprises With Gorilla Grodd Teaser

[Warning: Spoilers ahead for Tuesday's episode of The Flash, Crazy For You."]

Barry (Grant Gustin) had his hands full in Tuesday's episode, with Peek-a-Boo (Britne Oldford) telaporting all about town, Pied Piper (Andy Mientus) escaping from S.T.A.R. Labs, and Linda Park (Malese Jow) helping Barry's dating life speed along.

See more 'The Flash': Every Major DC Character on The CW Series

But the final scene, set beneath Central City, teased a beast that could put Barry's life in true danger.

Following the episode executive producer Greg Berlanti tweeted "What did you all think? #theflash #groddlives." That's a reference is to Gorilla Grod, who in the comics is a genius gorilla with the ability to control people with his mind.

The Flash team hasn't revealed when Grod will make his appearance, but Barry will have his hands full in the meantime. 

Pied Piper was in lockup under S.T.A.R. Labs after attempting to kill Barry (and a lot of other people) last week. But he played his big card — claiming to know where Ronnie Raymond (Robbie Amell) was.

For months after his apparent death the night of the particle accelerator accident, Ronnie's fiancee Kaitlin (Danielle Panabaker) thought he was dead. But he's recently reemerged with a bad attitude and serious fire-wielding powers. 

Read more 'The Flash' Villain Teases "Personal" Mission to Destroy Dr. Wells

Hartley led Cisco to the shadow of Dr. Martin Stein (Victor Garber), a S.T.A.R. Labs scientist who was revealed to be one-half of Firestorm. Stein and Ronnie have fused and make up powerful entity.

"He's schizophrenic, doesn't know what's happening, he's confused and dangerous to the people around him," Amell told The Hollywood Reporter of Firestorm last year. 

Meanwhile, Barry's secret identity is in jeopardy. Iris (Candice Patton) snapped a photo of him on the fly, and he landed on the front page of the paper. This could certainly come back to bite him, with a guy as smart as Hartley probably able to discern his secret from the photo.

Speaking of secret identities, in a touching scene, Barry's father Henry (John Wesley Shipp) spoke to his son from prison, all but revealing he knew Barry was The Flash.

"If The Flash were my son, I'd tell him it's a dangerous world so be careful," he said, choking up. Then I'd tell him he's a hero and he's saving a lot of lives.  (Read what Shipp told THR about the scene here.)

The Flash airs at 8 p.m. Tuesdays on The CW.

Email: Aaron.Couch@THR.com
Twitter: @AaronCouch