It could be that the snake has an ancient origin. Maybe it was once a pet of a powerful dark wizard from long ago, and through some magical event, it became Harry's familiar. This would add a sense of mystery and a connection to the past in the fanfiction story.
In some fanfictions, the snake familiar could be from a hidden part of the Forbidden Forest. There might be a special nest of magical snakes, and Harry discovers this one snake that has a unique connection with him.
One common trait could be its intelligence. Snakes are often depicted as smart in wizarding lore, so it might be able to understand complex commands or situations. Another trait could be loyalty to Harry.
In a fanfiction, the snake familiar could be a reincarnation of an ancient wizard who was wronged. It chooses Harry as its new master because it senses his pure heart and the power within him. The snake could have extraordinary abilities, such as the power to turn invisible at will or the ability to create illusions to deceive enemies. Harry would have to learn to trust this strange familiar and work with it to overcome various challenges.
Perhaps the snake familiar is from a different magical dimension. It has knowledge of magic that is unknown to the wizarding world of Harry Potter. As Harry bonds with it, he learns new spells and techniques that give him an edge in his battles. For instance, it could teach him how to manipulate time on a small scale, which he uses to outwit his foes.
In the fanfiction, the snake familiar could be a symbol of Harry's connection to a different side of magic. It might help him in his search for Horcruxes, for example, by being able to sense dark magic. It could also be a form of protection, scaring off those who would harm Harry with its intimidating presence.
Well, it could. For instance, it may have the power of invisibility at times. This would help Harry in his adventures as the snake could slither around unseen, gathering information or creating diversions. It gives a new dimension to the story and makes the snake a more interesting and useful familiar.
One possible scenario in such a fanfiction could be that Harry discovers the snake in the Forbidden Forest. The snake might be a rare and intelligent species, perhaps a Basilisk hybrid. It could communicate with Harry through Parseltongue and help him in his adventures, like warning him of approaching danger or finding hidden passages in Hogwarts.
One interesting 'Harry Snake Familiar' fanfic could be one where Harry discovers his snake familiar has unique magical abilities that help him in his adventures at Hogwarts. For example, the snake might be able to sense dark magic from a distance, allowing Harry to be more aware of potential threats.
The protagonist's familiar was a snake.
Well, a plotline might involve the snake familiar getting into trouble. For example, it could be mistaken for a dark creature by the Ministry of Magic. Harry then has to prove that his snake is not evil. Or perhaps the snake helps Harry discover a hidden part of Hogwarts. Since snakes are often associated with secrets, it could lead him to a secret chamber or passage that no one else knows about. And this could be a key to solving a mystery or finding a powerful magical item.
It could be from a hidden nest in the Forbidden Forest. There might be a species of snake there that has not been fully discovered by the wizarding community, and Harry somehow forms a bond with one of them.