This past weekend, people walking around downtown Denver may have run into their favorite super heroes, super villains or maybe even something totally unrecognizable. It's all part of the fourth annual Denver Comic Con, an event that organizers say brought in 101,500 people to the Colorado Convention Center.

Convention attendees dressed in elaborate getups are called cosplayers, short for costume play. Their outfits can take hours, weeks, days, or months to complete -- 44-year-old Phil Windsor spent 13 months on his Starcraft reaper costume.

We caught up with three attendees and asked them what they were wearing, and why. 

Blake Martin, 31, dressed as the Batman villain Mr. Freeze on May 24, 2015.
(Megan Arellano/CPR News)

Blake Martin, 31: Who are you supposed to be?
Mr. Freeze, the Batman villain.

What part of it was the most difficult to buy or to make?
The chest piece and the helmet.

Why is that? How did you do it?
Wiring. My friend over there actually did the wiring. He's an electrical engineer. This is EVA foam. I had one of my good friends help out with that. He's a shop owner, and his shop is McCalistan Armory in Salt Lake City. It's all EVA foam and paint and wiring. [The helmet] is actually a bulb from a street lamp.

So, how did you decide to play Mr. Freeze?
I'm in a group called Nerds of Play, and they wanted to do Batman villains, and I was like, I'll do Mr. Freeze. To me, he's the coolest villain, pun intended, I guess?

He's not really bad. He's just trying to do what he can to save his wife, and he'll do anything to do it, no matter who gets in the way. If he ever finds the cure, you probably won't see him as a bad guy anymore. 

Tara Broderick, 27, dressed as Machiko Noguchi on May 23, 2015.
(Megan Arellano/CPR News)

Tara Broderick, 27: What are you cosplaying today?Machiko Noguchi, a character from the Aliens vs Predators comic books.

How long did it take you to make this?
About four months. Lately I've been spending all day on it, and running on about three hours of sleep. It's been nonstop.

Why did you choose to dress as Machiko Noguchi?
She's a strong female character, which I love cosplaying as. I love this part of the franchise too. 

Do you have anything in common with her?
She's strong, she does whatever she wants and she has convictions that she sticks to, which is really important to me.

Why do you cosplay?
I like being creative and [my husband] likes being creative. We've never really been able to find something that we can do together, but this is something that we can do now as a family, and that's what's important. Plus, it's a confidence booster and it shows my daughter a whole new world.

Caroline Maggard, 21, dressed as her own character on May 23, 2015.
(Megan Arellano/CPR News)

Caroline Maggard, 21

What are you dressed as today?
It's just an original character. Have you ever played BloodRayne? It'd be kinda in that realm, it's a vampire game.  

What do you think her personality is like?
I would say very isolated, kind of a badass I guess. She probably does a lot of things herself.

Is this character different from who you are in real life?
She's a lot more brave than I would be. A lot more willing to take on stuff than I would be.  

How is dressing as your own character different?
A lot of people ask what I'm from, and I just have to say original character. That's a little bit different. 

It's kinda nice, a lot of people when they dress up as someone, they get into their character, and set as that. I can do what I want, and that's nice.