Justin Bieber can't stop getting tattoos — or at least he won't stop. The 19-year-old pop star appears to be averaging about one new piece of body art a month for 2013. His latest, as unveiled when he attended the premier for pal Jaden Smith's new film, "After Earth," appears to be a rendering of a knight in shining armor on the inside of his left forearm, according to Splash News. That happens to be the arm where he's put most of his new ink, including a tiger head on his bicep and an angel by his wrist that first appeared during his European tour (also, check out that owl tattoo, above. Was that drawn by a 16-year-old?). It won't be long now before Bieber is sporting a full sleeve on his left arm.