Yeo Jin Goo is growing up in front of our very eyes! Now that's he's 18 years old, the talented child actor is officially making his transition into adult leading roles by playing a villainous king opposite Jang Geun Suk in the upcoming fusion sageuk Daebak. To remember just how adorable and tiny Yeo Jin Goo once was, let's take a little stroll down memory lane to look at how he's grown over the years!

1. LOOK AT THIS FACE! I just want to pat him on the head and give him a pet kitten to hold.

2. Yeo Jin Goo's big acting debut was at the ripe old age of 8 in Sad Movie.

3. Posing with fellow child star Kim Yoo Jung on the set of Iljimae (2008)

4. Look at his dapper little outfit at the Giant press conference! (2010)

5. I'm not 100% sure where this adorable photoshoot fits into the timeline, but look at him! That vest! The clock! Every single thing about this is awww-worthy.

6. Four years after their first pairing, he teamed up with Kim Yoo Jung again for The Moon that Embraces the Sun (2012).

7. Yeo Jin Goo may have been the younger version of Yoochun's character in I Miss You (2012), but his crying face was already leading man material. When he cries, I cry. End of story.

8. Even though Yeo Jin Goo's Potato Star costar Ha Yeon Soo was 7 years older than he was, they basically looked the same age. How is that possible? (2013)

9. How cute is he in this Officiel Hommes shoot in 2013?

10. Posing with Yoon Si Yoon at the Mr. Perfect press conference in 2014

11. Uhhhh he was only 16 years old for this Marie Claire shoot in 2014. Are my eyes broken? He looks 26!

12. And yet somehow, he looked way closer to his age the next year for Orange Marmalade (2015). 

13.....But THEN you have this Vogue shoot, also in 2015. What is this wizardry? Time travel? It's the only possible answer.

14. Yeo Jin Goo's recent interview and pictorial with W Korea was all about his transition into "adult" roles, which they apparently interpreted by dressing him up like a lounge lizard and having him hold cigarettes and glasses of alcohol. *Shrugs*

15. Last, but not least, we have him as the dastardly villain in Daebak, premiering next week. Look at him all grown up and ready to go!

Can you believe how fast time has gone? Which Yeo Jin Goo phase was your favorite? You can see his latest role in the trailer for Daebak below, and don't forget to watch the series when it premieres on March 29 on DramaFever!