Hag - A savage, ugly witch covered in warts. They possess rudimentary magic; a simpler, tamer form of dark magic. Prefer to use their cunning and potions.

Hebridean Black - Dark, rough scaled dragon native to the Hebrides Islands of Scotland. It has ridges along its back, a tail with an arrow shape at it's tip, and purple eyes. See 'Dragon'

Herbicide Potion - A potion which kills or damages plants. Not for human consumption since it tastes foul and may affect the drinker's health. 

Herbology - The study and use of magical and non-magical plants for medicinal, protective or educational purposes. Each herb, fungi, tree and flower (magical and non-magical) has a unique personality and gift.

Hogwarts School of Witchcraft and Wizardry - British boarding school for magical students located somewhere in Scotland. Founded by Godric Gryffindor, Helga Hufflepuff, Rowena Ravenclaw and Salazar Slytherin. The school motto is 'Draco Dormiens Nunquam Titillandus' which is Latin for 'Never tickle a sleeping dragon'.

Hogwarts Express - A scarlet steam engine used to transport students from Kings Cross station in London to Hogwarts in Scotland.

Horned Slug - A type of slug with horns on it's head. When stewed, they are used as an ingredient in potions such as the Boil-Cure Potion.

Hover Charm - Leviosa. Wand movement: inward spiral then up. Can move an object that the caster is physically touching up and down. 

Hufflepuff - One of the houses at Hogwarts, founded by Helga Hufflepuff. Students traditionally show such traits as hard workers, patience and loyalty. The emblem is a badger, the house colours are yellow and black, and the house ghost is the Fat Friar.