Legends of Tomorrow is going bananas for Season 3. According to Variety's Danielle Turchiano, Gorilla Grodd was announced for the upcoming third season during The CW’s panel at the Television Critics Association press tour.
— Danielle Turchiano (@danielletbd) August 2, 2017
Though this will be Grodd's first Legends appearance, the character is an Arrowverse vet. Grodd made his full debut in The Flash Season 1 episode "Grodd Lives," though he was introduced as a stinger in "Fallout." He returned for Season 2 episode "Gorilla Warfare," where he was flung to Earth-2 by Cisco, and again in Season 3 episodes "Attack on Gorilla City" and "Attack on Central City." In his last appearance, Grodd was left defeated and captured on Earth-1 thanks to a team up between Team Flash and Gorilla City's Solovar. At the time of writing, it is unclear how Grodd will be involved in Legends Season 3 or what time period he will be from, considering the time-travelling nature of the series.
Grodd wasn't the only surprise to come out of the TCA press tour. Per DCLegendsTV, Brandon Routh will have a new role to play in Season 3: Ray Palmer's brother Sydney. It isn't a surprise that Sydney Palmer will appear, as his involvement was announced during the show's panel at Comic-Con International in San Diego. However, the fact that Routh will play the character is new, if unsurprising; in Legends Season 1 episode "Progeny," Sydney was revealed to look almost exactly like his brother Ray.
They just mentioned Sidney, Ray's no-good brother, and it sounds like @BrandonJRouth will also be playing him. (I wanted Tom Welling haha.)
— Legends of Tomorrow (@DCLegendsTV) August 2, 2017
“We are having an 80’s episode,” executive producer Phil Klemmer revealed at SDCC. “We’re going to investigate Ray Palmer’s childhood a bit and what formed the man… we’re going to meet [Ray's] mom.”
Premiering on the CW on Tuesday, October 10, DC’s Legends of Tomorrow’s third season will star Arthur Darvill a s Rip Hunter, Dominic Purcell as Mick Rory, Caity Lotz as Sara Lance, Brandon Routh as Ray Palmer, Nick Zano as Nick Heywood, Victor Garber as Professor Martin Stein and Franz Drameh as Jefferson “Jax” Jackson.