Auto-translated
I suggest the following creature:
--------------------------------------------------------------------------------------
Tokolosh (level 3)
Attack - 8
Defense - 4
Damage -
Health - 8
Speed - 4
Initiative - 9
Mana - 10
Spells:
Weakness
Disruptive Ray
Abilities: Undead, Curse, Warlock, Magic Resistance 25%, Fire Resistance 50%
Description: If a shaman is offended, he creates a tokolosh from dead bodies. Although after the transformation, their body shrinks to the size of a small child, they cause terrible destruction, attack people, and damage their property, often casting curses. To bring a tokolosh to life, a special spell must be cast, and a red-hot poker must be used to make a hole in its skull, which is why the tokolosh is immune to magical attacks, and especially to Fire.
--------------------------------------------------------------------------------------
Model of a demon, but white-gray in color and without wings. Don't forget the hole above the eyes!
Added 11 hours and 2 minutes ago
http://senspeople.ru/wp-content/uploads/2016/05/tokolosh-zloy-karlik-nasiluushiy-ludey.jpg
I would bring back to the description "he creates a tokolosh from dead bodies, from which he removes the tongue and eyes." and we need to somehow bring back to the description their ability to be invisible!
Weakness and Disruptive Ray are pretty cool for level 3, and according to the description, they just cause mischief like gremlins - it's kind of called sabotage!
С уважением, Psatkha (Псатха) 
---------------------------------------------
Неудачное планирование ведёт к неудаче ...
NCF - мод, добавляющий дополнительных существ в HeroesV 3.1

---------------------------------------------
Неудачное планирование ведёт к неудаче ...
NCF - мод, добавляющий дополнительных существ в HeroesV 3.1