The "Vault 101 Tattoo" available in the Fallout Pack.
Tattoos are one of Brink's Character Customization options. There are a variety of tattoos available at the beginning of the game, separated into two main body areas, torso (chest, arm sleeves, etc.) and face. However, tattoos are one of the character creation options that are not interchangeable once the character has been confirmed.
Some types of tattoos are only obtained through special packs, such as the DOOM Pack, Fallout Pack, Psycho Pack, and Spec Ops Pack.