Justin Bieber is full of surprises this week! The "Boyfriend" singer dropped by The Ellen DeGeneres Show to celebrate the host's 57th birthday on Thursday, Jan. 29 -- and showed off a new hairdo to boot!

The 20-year-old came out from backstage carrying flowers and some Calvin Klein underwear for DeGeneres, a nod to his recent modeling gig. A far change from his trademark hairstyle, his blonde locks were also swept to the side.

DeGeneres reminisced about the first time Bieber ever appeared on the show (when he was 15!), which just so happened to be his first time on a daytime talk show. A lot, of course, has happened since then.

"I haven't been on TV in a while so I'm a little nervous," Bieber said. He added of his upcoming Comedy Central Roast: "I think its just cool to laugh at yourself. I've done some things that might not have been the greatest. I just want to be able to laugh about it and own up to some of the things."

Hours after he filmed his appearance, Bieber apologized for his past "arrogant" behavior in a Facebook video message. Some of his recent troubles have included a DUI arrest and assaulting a limo driver in January 2014, and egging a California neighbor's home in July 2014.

In the video, Bieber explained further just how anxious he was while speaking with DeGeneres. "I think I was nervous because I was afraid of what people are thinking about me right now. It's been a minute since I've been in a public appearance, and I didn't want to come off arrogant or conceited or basically how I’ve been acting the past year, year and a half," he said.

"Just being young and growing up in this business is hard. Just growing up in general is hard," he added. "I'm not that kid, I'm a person who genuinely cares."

Watch Bieber's appearance on The Ellen DeGeneres Show above!