Elf
| Sentience | Sentient |
| Eye colour | Varies |
| Hair colour | Bald |
| Height of average adult | 3" |
| Mortality | Mortal |
| Distinction | Short and skinny |
| Affiliation | Their master |
| Status | Being |
"A house-elf must be set free, sir. And the family will never set Dobby free... Dobby will serve the family until he dies, sir...." -DescriptionA house-elf (sometimes also referred to as just elves) is a magical creature which is immensely devoted and loyal to the one designated as their master.
House-elves serve wizards and witches and are usually found under the employment of old wizarding families taking residence in elaborate establishments, like mansions, and must do everything that their masters command unless they are freed. A house-elf can only be freed when their master presents them with clothes.
House-elves have their own brand of wandless magic which, despite their small physical size, is very powerful.
Magic
"Fight, fight for my master, the defender of the house-elves! Fight for master Regulus! Fight!" -Kreacher leading the house-elves during the Battle of HogwartsAll house-elves have their own brand of powerful magic, which allows them to perform tasks, such as Apparating, where wizards and witches cannot. More than just a mere housekeeper, a house-elf is a ruthless protector of those to whom they give their allegance. In 1993, Dobby protected Harry Potter by using his magic to throw his former master, Lucius Malfoy, across the floor.
Their magic is limited by the lack of a wand. However, unlike some other magical beings, the house-elf is actually quite happy not to own a wand, as they do not require one for their daily activities. Apart from routine domestic tasks, house-elves usually have to obtain permission from their master before they would use their own brand of magic for other things. Although a house-elf may rarely act without permission, they would have to punish themselves for these acts.
It is implied that with a wand and the proper knowledge, a house-elf may be able to do other magic, as Winky was falsely accused of using the Morsmordre spell to conjure the Dark Mark.
Physical appearance
House-elves are between two to three feet tall, with spindly arms and legs and over-sized heads and eyes. They have pointed, bat-like ears and high, squeaky voices. Rather than conventional clothing, house-elves wear discarded items like pillowcases and tea-towels.
(source:Harry Potter Wikia)