Sgt. Wu is one of the greatest mysteries on "Grimm." After two and a half seasons of the NBC show, we pretty much only know that he's a cop, single, a cat lover, a foodie, and a reliable source of sarcastic one-liners. Even Reggie Lee, the actor who plays Wu, doesn't have that many more details to offer.

All that changes this week with the "Mommy Dearest" episode, in which Wu's pregnant childhood friend (and unrequited love) is attacked by an amniotic-fluid-eating Wesen called an Aswang. We also meet his cousin, find out that he despises pig knuckles and speaks Tagalog, and hear more about his cat. We see a young Wu in a flashback and watch as he catches his first true glimpse of the supernatural side of Portland. Even his first name is revealed.

Watch a clip from "Mommy Dearest":

Yahoo TV caught up with Lee via telephone to talk about the "eight frustrating, exhilarating, fulfilling days" it took to make the episode. He explained, "It was hard. David [Giuntoli], who plays our lead, gets to have his emotional arc span at least the whole 22-episode season, but it was like they stuffed all of Wu's crying, jagging, scared, and heroic scenes into one episode. It was a blur while we shot it, but after seeing the finished product, I could not be more proud."

You grew up in the Philippines, and as it turns out, so did Wu. The Aswang legend hails from those parts as well. Had you heard of it before?
The writers came to me and asked me if I knew of any Filipino folklore we could use for an episode fashioned around my culture and around Wu seeing something for the first time. I said, "Are you kidding? There are so many." It's a small island, but the people there make up a lot of stories. So I gave them a list. And just like in the episode, I grew up being told these stories by my grandma and my parents, and you'd even hear them on the street. This is probably the most popular one. And the most freaky. I swear to God I was freaked out about the Aswang when I was a kid in the Philippines.

The gang learns more about the Aswang in this sneak peek of "Grimm":

Must have been cool to incorporate your heritage and native tongue as well as see several other Filipinos on set.
I have played every kind of Asian under the sun, but this is probably only the second time I have played Filipino. I am so close to my culture, so it is icing on the cake to be able to tell a Filipino story, and I had worked with two of the guest actors before. It's such a small community of Asian actors. Being a genre show, we have rabid fans, but the Filipinos take it to the next level. They are so big on sci-fi and they follow the show religiously. The minute they heard we were doing Aswang, they blew me up on Twitter. It is nice for me to represent that way.

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Must also be nice to flesh out Wu's story a little more.
It has been a long time coming for Wu to have some sort of backstory moment and also just to see something. Finally, I got to show the other side of Wu. This is a dude who is always in control and cracking jokes. To figure out how to blend his sarcasm with the vulnerability he feels about saving his friend and seeing a Wesen felt like being a kid in a candy store. Giving him those added dimensions starts to form a real person, and the more I find out about him, the more I have to work with and the more joyous it becomes.

And we finally find out his first name — Drew.
I think it is hilarious that we're in the third season and just now finding out the guy's first name. And the reveal goes by almost in passing as if we've known it all along. The whole time I had teased that I wanted my name to be Sgt. Lou Wu. Every prop that I have had up until now, like the files I hand to people, says reporting officer Sgt. L Wu. But they couldn't clear it, so it morphed into another rhyming name. All those reports are defunct now.

So much about him is a mystery to viewers. Have you dreamed up his whole backstory?
Yes, that's my job. I have to try to make a character as fully formed as I can from what bits and pieces of information they've given me. I've made up why I'm sarcastic. I researched sarcasm and found out that it often comes from insecurity, so I tried to deduce what Wu would be insecure about. I figured that's easy because he grew up in an Asian family, so obviously he is under the pressure to achieve. I imagined that my father was a really good cop, and I am trying hard to follow in his footsteps. I even have names for my fictional parents.

Do you prefer him staying in the dark about the Wesen world, or do you hope he gets let into the club now that he's seen a beast?
It's akin to being the one left out of school activities. Reggie wants to be part of the gang that goes on the trek to solve the mystery. But Wu doesn't know any better. Who knows? This episode could be part of the indoctrination. I think the writers are toying with the idea of adding another person to Nick's Grimm fold. The effects of what he saw are long lasting. He isn't immediately over what he sees.

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Coolest fan moment?
I have the biggest sweet tooth, and just recently a doughnut shop in Portland called Pip's Original introduced a doughnut inspired by me called the Dirty Wu. It is a cinnamon-sugar doughnut with sea salt, drizzled with honey and Nutella. It is the best f---ing thing I've ever tasted in my whole life. I went in and met the owner, and there was a line out the door to get a Dirty Wu. It happened during Oscar weekend, and I think it is better than an Oscar. I have a doughnut named after my character. I have made it.

Has shooting in Portland made you a foodie?
Absolutely. It is the best place in the world to eat dessert or breakfast. There are so many great places. I kid you not, my cholesterol level was way up at the end of Season 1, and suddenly, for the first time in my life, I had to watch what I was eating. But I love it there. It feels like I am on vacation every time I land there because there are gorgeous surroundings, amazing food, and really, really sweet and interesting people. And did I mention someone there created a doughnut in my honor?

"Grimm" airs Fridays at 9 p.m. on NBC.