The most USELESS monster.

I understand that perfectly, but it's more about the "early game" or the lack of alternatives – these are specific cases. When large-scale battles take place, I don't think such a unit is an indispensable asset, although the zeal and luck of Leprechauns and Satyrs have saved me more than once, even though you won't find their dwellings everywhere, and portals are expensive...

P.S.: This applies to all neutral creatures...