Producers of "The Flash" teased audiences at WonderCon with previews of the final episode and hints at season 2.

During the panel for CW's "The Flash," a trailer was shown for the final episodes where a number of new characters and glimpses of further crossovers from "Arrow" were shown. Among the characters that were shown in the trailer were Ray Palmer/A.T.O.M., Gorilla Grodd, and DC supervillainess Red Bee.

After the trailer, a panel discussion was held with co-creator and co-executive producer Andrew Kreisberg and cast members Carlos Valdes (Cisco Ramon), Candice Patton (Iris West), and Danielle Panabaker (Caitlin Snow) in which a number of hints were revealed. Among the biggest surprises was that actress Panabaker confirmed that her character will transform into the antihero and occasional tragic villain Killer Frost, who has the power to manipulate temperature into a deadly ice form.

She said, "You're gonna see her sooner than you think."

Meanwhile, Kreisberg said that the second season will add classic "The Flash" villains such as Mirror Master and Dr. Alchemy and that they would add Wally West (the first Kid Flash and the second Flash in DC Comics) as a protégé of Barry Allen.

Kreisberg also hinted that the show's characters will likely get glimpses into alternate timelines. However, Kreisberg did not confirm anything. For some time, fans have speculated that DC Comic and CW will likely adapt "Flashpoint Crisis" through the series--which refers to the DC Comics event in 2011 which saw Barry Allen travel backwards in time battling The Reverse Flash and resetting major events in the DC Universe, affecting all major characters from Batman to Superman and more. 

During the panel, it was also revealed that the events of Episode 15 will be erased due to The Flash accidentally traveling backward in time. The events will reappear in some form before the current season ends. However, it is unknown which episode the events will happen.

The final slate of Season 1 episodes will begin on April 14 after one week off. The series airs at 8 pm EDT Tuesday on the CW Network.