The basilisk of our world is radically different from that of the one in the HP world. This creature was greatly feared, with its deadly gaze, scorching breath, and its poison-covered skin. It was also known as a cockatrice, as it was part chicken, part serpent--having the head of a rooster, the wings of a bird, and the tail of a serpent. Its name came from the Greek word basileus and basiliskos, meaning "little king." Some believe that it is modeled after the crustes (horned viper), or the yellow viper.
The way a basilisk was produced made it a very rare creature. A 7-year-old (some legends say 9-year-old) chicken lays an egg in a dunghill during the time that the Sirius star was high in the heavens, then the egg is hatched under a toad or serpent who has sat on it for nine years. Thus saying, it would require patience and VERY special circumstances to create this powerful creature. It seems fitting that only those who are gifted and able to care for the eggs form of this creature have the right to own and use one, though basilisks usually killed their creators. The only thing able to kill basilisks are other basilisks, prepared and courageous (or stupid) humans, and weasels, who supposedly were immune to its deadly gaze.
The Harry Potter version of the basilisk, on the other hand, is very different. An extremely poisonous, giant serpent (can be up to 50 feet in length), it is a wizard-bred creature. Being brilliant green in color, it has long, thin saber-like fangs and bright yellow eyes. Its life-span is 900 years with an adequate food source, and since they eat most vertebrates (organisms with backbones), this can easily happen. The male has a scarlet plume on its head, but basilisks are usually bred magically rather than conventionally. It is illegal to breed basilisks, and this law is rarely broken, as you must know Parselmouth to control one, which is rare among all wizards and witches.
Similar to actual legend is the way a basilisk is naturally bred. It is born from a chicken's egg hatched under a toad, but no more details are given beyond that. The HP basilisk also has a deadly stare, but its means of slaying may be different. Spiders are their mortal enemy, so spiders flee from the great serpent, and a rooster's crow is the only known natural way a basilisk can be killed. It can also be assumed that the phoenix is immune to the basilisk's gaze, as Fawkes seemed unaffected by the basilisk in the Chamber of Secrets. When the basilisk's eyes were pecked out, it still was fairly easy for it to find Harry, so it must have an acute sense of smell.
If Harry had known and used a Stunning Spell on the basilisk, he may well have died. It is also very possible that the basilisk and dragon are related in the HP books. If so, then the basilisk would certaintly have diamond-hard skin, much like a dragon's. The Stunning Spell would have bounced off, and it would have given the basilisk a chance to finish Harry off.
Interesting Facts
The Yeti is a creature of great speculation in the real world and is a fascinating subject of stories and tales. Its identity is never really proved, or grasped, but there are always those believers who hope more than anything that this animal will be brought into the light, and we will know the truth of the Yeti.
First and foremost, the Yeti has countless names, and many "cousins" and "relatives." I will simply be covering the legend of the Yeti, or Abominable Snowman. That is the creature most commonly seen in the Himalayan Mountain range, mostly on Mount Everest. The various names of this creature are the Yeti, Abominable Snowman, Metoh-Kangmi, Yeh-teh, Meh-teh, and Raksha (a Sanskrit word for "demon").
The Yeti is allegedly between 7 and 10 feet tall, and has feet twice the size of those of a normal human's. It is commonly described as being bad smelling and very hairy, with hair (usually a lighter color, or a light brown) that covers its whole body. It mostly makes loud whistling noises, but also grunts, and makes strange guttural noises. He also walks upright, and is very much like a man, other than his height, hair, and size.
The HP Yeti is different in many aspects, yet the same in many others. First of all, the other names for this creature in the HP world are Bigfoot and Abominable Snowman. Its Ministry of Magic rating is XXXX (dangerous/requires specialist knowledge/skilled wizard may handle), and is native to Tibet.
In the HP universe, the Yeti can be up to 15 feet tall, and its hair is always of the purest white, which also, like the "real" Yeti, covers its whole body. It fears fire, devours everything it comes across, and is believed to be a relative of the Troll.
In both the HP world and the real world, the Yeti is an enigma. It is always being sought after, and everyone wants to prove its existence. One day, maybe, this creature's stance on Earth may change, and may become not just a myth, but fact.