Selpek is not mentioned in Harry Potter nor does it exist in the real world.
Harry Potter. Your arguments are invalid. -Ting Ching
a basilisk is a fictional character, and even if it were real, it would eat most anything that has a heartbeat and blood. legend holds it to be a bloodthirsty monster, where if you look straight into its eyes, you die. yet if you look at it in a mirror or reflection of some type, then you would only be petrified.
Give him owl-food.
The house elves do. It says in book 4.
No, there is not.
Harry Potter. Your arguments are invalid. -Ting Ching
He ate everything except for the humbugs
If you mean at Hogwarts, then it comes from the kitchens. The trio first discover the kitchens in book four, Harry Potter and the Goblet of Fire, later in which Hermione makes the Society for the Promotion of Elvish Welfare (S. P. E. W.)
Please note that Harry Potter is a fictional story.Using their magic, they can do pretty much anything... There are a few restrictions, mentioned in the books. For example, they usually can't raise the dead, and make them live again, nor can they produce food out of nothing.
Chocolate. That was said to be good to get over a dementor attack.
Hogwarts students get breakfast, lunch and dinner everyday. There is a wide selection of food available in the Great Hall. In the fourth book we learn this is prepared by house elves.