Just to clear up any confusion, here's a guide of what tattoo represents which person:
Black Dog: Sirius Black (obviously…)
Red Lion with Blue Eyes: Ron Weasley (died along with Hermione in a struggle with Death Eaters; Voldemort wasn't there, but it was a big battle)
Fluffy brown owl: Hermione Granger
Tawny wolf: Remus Lupin (died along with Charlie, Mr. and Mrs. Weasley, Draco, Severus, and Vodlemort in the Final Battle)
Red Dragon: Charlie Weasley ('cause he likes dragons, and has red hair -)
Lion and lioness: Mr. and Mrs. Weasley
White ferret: Draco Malfoy (he turned to the 'light' side as a spy)
Black raven: Severus Snape (also a spy)
Dark green snake with slitted red eyes: Voldemort (died in the final battle)
Dark green and black phoenix with gold and red fire: Harry Potter (symbolically; he put his 'dead' past behind him; he had to be merciless during the war, and he killed people, thus the dark green and black; his Slytherin side. The Gryffindor flames are his 'spiritual rebirth' ... or something like that)