What does it mean that the cartoon character (girl) has a wolf tattoo on his back?

You should be talking about the cover picture of the swan song of the king angel of the internet.

There are many beautiful girls with tattoos in the animation, such as the following:

Seurat Wuyin is a striking beauty among exorcists in Qing Dynasty, but what is more striking than herself is the pink tattoo sandwiched in Europe. This tattoo is striking because every time she fights with the enemy, she summons the sealed magic sword through the tattoo on her chest, which is very attractive every time she sees it.

Nami's tattoo has a very special significance, because she was adopted by Belmir who liked oranges when she was young, and then Belmir died to protect Nami, and got a tattoo on her arm in memory.

Lisesharte Atismata's tattoo is on her abdomen, but she doesn't like it at all. Because every time I think about this tattoo, she is afraid that the secret that she is "the property of the old empire" will be leaked, afraid!