Wolves have been a major player in our species' culture anywhere they and man have shared space. The complexity of the role played by wolves has lead of a rich tapestry of sometimes conflicting symbolism that surrounds them. Wolves litter the heraldry of Europe, haunt the myths and fairy tales of Japan, America, Northern Europe and Northern Asia.
Wolves represent nature first and foremost. In cultures at odds with nature, like much of Europe after the fall of the Roman Empire, wolves represent the failing of civilization and the encroaching of monsters from the woods. As symbols of nature, the wolf can represent the animal nature of man and the struggle between society and anarchy. Wolves are commonly the villain in stories found in these kinds of society, from chasing Red Riding Hood to blowing down the Little Pig's houses.
Wolves are intensely social, with some of the most complicated social structures of any animals besides man, and part of the symbolism of wolf tattoos concerns itself with this characteristic. Wolves belong to packs, with strong relationships between members of the pack. This in-pack/out-pack dichotomy makes wolves attractive symbols to those interested in representing group unity or solidarity. By embracing the image of the wolf (can be done with lettering tattoo designs, like the image below), some people seem interested in demonstrating that they too, are part of a pack, with all that suggests.
Wolves also represent a threat to humans, being one of the few animals that were capable of threatening human dominance. As a result, wolf tattoos can represent the a menace or violence that the tattoo bearer feels. Centuries of wolves as the villain of folk lore and legend has made the image of the wolf one that is powerful, dangerous and intelligent. Ancient tattoos of animals often represented the tattoo bearer's identification with the animal in question, and the complex mixture of threat and solidarity makes the wolf a powerful symbol.
Native American symbolism surrounding the wolf is more nuanced than European myths surrounding them. For Native Americans, the wolf was more than just a threat or symbol of unity, it was a teacher and a mentor as well as a representation of a certain wisdom found in the natural world. People who identify with Native American tradition often sieze on this symbolism to identify their awareness of the natural world, as well as laying claim to the strength, freedom and power that wolves represented to the Native Americans.
Finally, there are many famous mythological wolves that have cropped up in various different cultures over the years. These range from terrifying (like the wolf Fenrir, whose appearance heralded the end times for Norse religions) to the humorous (the Wolf Whistle originating in cartoon representations of the horny wolf). Native Americans had wolf spirits which could be communed with for knowledge or victory in battle, while the Japanese word for wolf sounds identical to the word used to describe the various gods. Modern supernatural beliefs about wolves have made the wolf an attractive image in pop culture as well, leading to an increase in the number and variety of wolf tattoos.