Oliver Queen has many scars on his body from the time he spent shipwrecked on Lian Yu. He also came back with a couple of tattoos, one on his chest and the other on his torso.
The tattoo on his left pectoral muscle is of an eight-pointed star. It signifies that he is Bratva, a member of the Russian mafia. The meaning of the star is revealed in the episode Lone Gunman when he needs information from the Russian mob to track down the assassin Deadshot.
On the right side of his abdomen, Oliver has four Chinese symbols. The symbols appear to be random and individually mean mouse, ginger, Yao (a surname), and pig. We can only assume that the producers of the show gave him this tattoo because it looks cool and isn’t supposed to have a hidden meaning.
He also has a dragon tattoo on his back by his left shoulder. The dragon is very similar to the one on Shado’s back.