Echo Kellum Talks Oliver & Barry’s ‘Freaky Friday’ Moment in Arrowverse Crossover

Fans of the Arrowverse can't wait to see Oliver Queen and Barry Allen switch places in the upcoming “Elseworlds” crossover.

Stephen Amell recently tweeted a photo of himself in the Flash costume alongside Grant Gustin wearing his Green Arrow suit, but nobody knows quite what to expect when the crossover kicks off in December.

ExtraTV.com caught up with “Arrow” star Echo Kellum, who teased, “I'm sure you've seen the pictures of Stephen and Grant having kind of a 'Freaky Friday'/'Quantum Leap' aspect going on. I think it is something that people have never seen.”

How did Stephen do in the Flash suit? “I think he did a pretty great job. As far as the comfort, I can't speak to that,” Echo said with a laugh. “It was very much a pinch-myself moment seeing him work with Grant. I thought 'This is the coolest thing ever.'”

What about Grant's bow and arrow skills? “He's stepping it up. He did shoot me by accident, but I do feel like he is finally getting it. He has got some good form.”

Kellum was also excited to have Ruby Rose join the crossover as Batwoman. “To see Batwoman come into our show is just the craziest, most surreal thing in the world… Batwoman and that character, and what that symbolizes, is just so huge. Ruby Rose is killing it, and I just can't wait for people to see it.”

When asked about the possibility of Batwoman switching places with Supergirl, he asked, “If you have the photos, please send them to me, I would love to see them!”

Echo also dished on his character Curtis Holt aka Mr. Terrific and how he fits into the plot. Kellum said, "Curtis will definitely be in the mix… he will definitely have a footprint on the crossover and will be an important aspect of what's going on in 'Elseworlds.'”

He added, “A cool aspect for me personally in the crossover was getting to work with (original "Flash" star) John Wesley Shipp. That was a really surreal and cool experience that I never thought I would get to do being a fan of that show from the '90s.”