As the complete opposite of the dark tone of "Arrow," CW's spinoff series, "The Flash," provided a more light-hearted approach to superheroes since its first episode. With Grant Gustin's lovable but geeky Barry Allen, and Carlos Valdes's comic relief Cisco Ramon, the appeal of the series lies in the fact that it's a break from the grittiness of most superhero adaptations.

It also had no problem pulling in known characters, like casting the original CBS's Flash from the 1990's, John Wesley Shipp as the current hero's father. However, for the return of the series, there are more villains expected to be seen - one surprise in particular is Mark Hamill as The Trickster.

Screen Rant noted that the most dedicated fans know that Hamill has played The Trickster in the 1990s series. However, it came as a surprise that he is not only appearing as a villain in "The Flash," or even a more modern take on the villain he once was - he's actually reprising his role as the same villain, and yes, the same character, twenty years later. The episode is set to air on March 31^st.

Of course, as with every epic villain, there's going to be a copycat, and for The Trickster, Devon Graye takes up the costume but as io9 pointed out, a shot of the original still shows that Hamill's character has plans of his own.

Before Hamill's appearance, there are more villains in line to attempt to make a mess out of Central City, among which include Liam McIntyre as the Weather Wizard for the episode, "Out of Time," for March 17, and the return of Wentworth Miller as Leonard Snart (aka Captain Cold) for "Rogue Time" alongside Peyton List as his sister Lisa Snart (aka Golden Glider) on March 24.

There also seems to be more insight about Barry's investigation on the death of his mother and it seems that more insight will be given to the matter as the teaser clip showed the possibility of the STAR Labs crew finding out the truth about Harrison Wells, as well as Barry's possible time-travel stint to the time his mother has been murdered.

Finally, it seems that they have given more and more screen time for Gorilla Grodd (albeit just a few seconds per reference) and if not this season, he could be the big baddie for the already greenlighted sophomore year.

There are definitely a few more surprises from the series before it wraps up its first season, but who else do you want to see make an appearance before then?

"The Flash" will return on March 17 on CW.