This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Hiisi (Finnish)
The Hiisi are goblin-like creatures that dwell in deep woods, inside mountains and in waters. The Hiisi has referred both to giants, who have moved giant rocks into formations, and to small creatures living in caves and crevasses. Giant’s kettles are in Finnish called Hiisi’s churn.
Hiisi were often small in size, on some occasions gigantic. Hiisi could travel in a noisy procession, and attack people who did not give way to them. If somebody left his door open, a Hiisi could come inside and steal something. If you were chased by a Hiisi you should seek safety in a cultivated area. In folklore, evil hiisi could not step inside areas sanctified by human cultivation.