Hiisi (plural: hiidet, Finnish goblins) are ancient spirits or gods of the forest. In a list of Finnish gods, written in 1551, Hiisi was mentioned as the forest god who helped hunters catch prey. Hiisi has also signified a holy place in a forest where people sacrificed for gods.

The Hiisi have been considered to both be giants who threw big rocks in piles, and small creatures living in caves or under rocks. Giant's kettles are in Finnish called Hiisi's churn (Hiidenkirnu).

In old poems, forests are called Hiisi's lands, and when going there, one must be protected with a magical iron gear.

The different types of Hiisi mentioned in spells are forest hiisi, water hiisi, mountain hiisi, and earth hiisi. They dwell in deep waters, inside the earth, inside mountains, in caves and holes in the forest.

In folklore, the Hiisi have in part turned from gods into devil-like creatures who attack, poison, cause accidents. Hiisi's sidekick is a flying creature Lempo.

But at the same time, the Hiisi have preserved their god-like status as forceful nature spirits that can be summoned in challenging situations. The shaman can summon individual goblins like the Lord of the Mountain with his powers, the Water Goblin with his terrors, or the whole family and nation of the Hiisi.

O Hiisi, come from Hiitola,
thou hump-backed from the home of gods
come hither with thy sons,
with thy sons and thy serving-girls,
with thy whole nation too,
with utmost speed to crush,
to eat this evil thing,
to lap this monstrous evil up.
Magic Songs of the Finns

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