Unlike other religions, Hindus consider tattoos to be sacred images and to not prohibit them. As Hinduism is a polytheistic religion, many religious tattoos focus on the various gods that pertain to the religion.
Ganesha has become a favorite Hindu symbol in tattoos in the west. He is the god with an elephant head and is known as the remover of obstacles.
Hanuman is the divine monkey chief and the ultimate devotee of Lord Rama, at one point actually tearing open his own heart to show that Lord Rama was kept there. Although not as popular as Krishna or Ganesha, the scene of the heart opening is one that is done in tattoos.