It could also be a snake from the Forbidden Forest. There are many unknown and mysterious creatures in there. A snake from that forest might be more in tune with the natural magic of Hogwarts. Harry, being the curious and kind - hearted person he is, might come across it during one of his adventures in the forest and start a friendship with it.
It could be Nagini. Even though in the original series she was more of a servant to Voldemort, in the fanfiction, she could have a different personality and form a bond with Harry.
The snake's help could represent an unexpected alliance. In the Harry Potter series, snakes are often seen as symbols of Slytherin, which is usually at odds with Harry. So it's significant as it breaks the stereotype of enmity between Gryffindor (represented by Harry) and Slytherin.
The snake might use its ability to move stealthily. It could spy on the enemies for Harry Potter. For example, it can slither into hidden places where humans can't easily reach and gather important information.
Well, in some fanfictions, he might find it in the Forbidden Forest during one of his adventures. Maybe it was injured and he felt a connection to it, so he decided to take it as a pet.
Perhaps he would name it 'Slyther', as a play on the Slytherin house name. Given that snakes are often associated with the Slytherin house in the Harry Potter universe, it would be a fitting name for his pet snake.
The snake could help Harry find his way around Hogwarts. You know, Hogwarts is a huge and complex place. The snake might be able to sense the different magical auras of different areas and lead Harry to where he needs to go, like the library when he has to study for an important exam or the Room of Requirement when he's in a tight spot.
Nagini is quite popular. Since she was Voldemort's snake in the original series, fanfiction often explores her backstory. Maybe she wasn't always evil but was forced into servitude. Another popular character could be a new snake created by the author. This snake might be a magical hybrid with unique powers, like the ability to change colors to blend into different environments and help Harry in his stealthy missions.
There probably are. In the 'Harry Potter' universe, Hufflepuff is known for its inclusivity. A fanfiction about a snake in Hufflepuff could involve the snake having special abilities or being a misunderstood character. Maybe it's a magical snake that helps Hufflepuff students in their studies or in a dangerous situation. Since Hufflepuff values loyalty and hard work, the snake could be part of a story that emphasizes these values in an unexpected way.
Well, in certain fanfiction scenarios, the snake might have a special bond with Harry Potter. Maybe it was once saved by Harry, and now it feels a sense of loyalty towards him. The snake could then use its unique skills, such as its ability to move stealthily through the Forbidden Forest, to gather information about threats against Harry. It could then lead Harry to safety or help him plan a counter - attack against his enemies.