Looks like Shawty Mane is back! Justin Bieber contributed to a new Sean Kingston song, on which he both sings and raps. The track is called "Won't Stop" off Kingston's new mixtape King of Kingz, which also features B.o.B, Soulja Boy Tell'em, Flo Rida and Akon.

"I see them coming/ They try to bring me down/ But I won't stop/ They want me in the ground/ But I won't stop/ 'Til I'm dead, I won't stop," Bieber sings on the track.

Then he raps, "Yeah they talk, yeah they talk/ They don't walk the walk I walk/ I won't stop 'til I drop, until then I reach the top/ I'mma walk to where I need to be, walk the path of destiny/ Definitely been neglected but God is always testing me/ Rest in peace to all the men that died who were protecting me/ People in this world just want to let it be/ John Lennon made it different/ Don't just let it be, set it free."

Kingston and Bieber's previous effort was the lighthearted romp "Eenie Meenie" in 2010. On the track, Kingston and Bieber sing about a heartbreaker. A video for the track came out in April of last year.

"I met Justin about two years ago, before he was the teenage phenom that he is now. I don't really have that same chemistry with some celebrities. God just made it happen," Kingston said back then.

In September, Kingston shared with MTV News that he and Bieber had been working on a mixtape together and that Bieber would be rapping on it. "[He's] pretty tight, nice for someone who doesn't do it that much," Kingston said of the singer's rhyming skills.

Last October, Bieber released a video displaying his rap skills under the moniker Shawty Mane. "You know Justin Bieber is not a rapper, and it would just be lame if I came out rapping," Bieber explained to MTV News. "It's lame anyway because I'm a pop singer, but I thought it was funny. I just did it as a joke. It wasn't like anything serious."

What do you think of Bieber's appearance on Sean Kingston's "Won't Stop"? Tell us in the comments.