Barry Allen has battled a lot of strange metahumans on The Flash, but Grodd is by far one of the weirdest, as he’s the only non-human from Earth One (sorry, King Shark) who’s been transformed by the particle accelerator. When we last saw the telepathic gorilla, he had been sucked into a portal leading to Earth Two and found himself in Gorilla City, a familiar locale from the comics. While it doesn’t look like that particular plot point will be revisited during the remainder of the Scarlet Speedster’s sophomore season, it’s recently been hinted at the TCA winter press tour that viewers will see a lot more of Grodd in Season 3.
Executive producer Andrew Kresiberg said it’s unlikely Grodd or the ape metropolis will return during Season 2, as their current focus on Zoom wouldn’t allow for a multi-episode arc. However, he did say (via Collider) that he’s hoping Grodd can play a big role in Season 3, comparing it to how Ra’s a Ghul was set up on Arrow. As Kreisberg put it:
I would liken the Gorilla City thing to Ra’s al Ghul. You know, you hear about 'the man from Nanda Parbat' in [Arrow] Season 1, and 'the man who showed Malcolm the way,' and then you met Nyssa, then in Season 3 you met Ra’s. So, it’s a long-term thing.
In terms of Grodd being built up to as a lead threat, that Ra’s al Ghul comparison is quite fitting. After Malcolm Merlyn alluded to Ra’s in Arrow Season 1 as the man in Nanda Parbat who helped him find purpose, Ra’s was then mentioned several times in Season 2, with his daughter Nyssa acting as the the League of Assassins’ main representative. It was only in Season 3 that Matt Nable’s version of the character was finally seen, and he served as Oliver Queen’s main enemy. Grodd actually has a leg up on Ra’s since he’s already appeared four times (five if you count those sewage workers being mauled in “Crazy for You”), so The Flash fans are quite familiar with him.
While Kreisberg didn’t go so far as to say Grodd would be Season 3’s main antagonist, akin to Reverse-Flash and Zoom’s roles, using him as an arc threat is a good idea. Grodd has been one of the Flash family’s greatest enemies since 1959, so he can easily be used for more than just one episode at a time, even if the VFX required to show him is trickier to pull off compared to the show’s other effects. Plus, now that he’s found other super intelligent gorillas on Earth Two, Grodd could even lead an army back to Earth One to conquer his former home, acting as an unofficial adaptation of the New 52 storyline “Gorilla Warfare.”
While Grodd won’t causing any more trouble on The Flash Season 2, fans can look forward to plenty of other villainous metahumans when the series resumes on Tuesday, January 19 at 8 p.m. EST on The CW.