From The Heroes of Might and Magic III wiki

Town: Dungeon

	Attack Skill	9	Damage	3-5
	Defense Skill	7	Health	22
	Speed	5	Shots	12
	Growth	6	Cost	250 gold
Special: No Melee Penalty

[edit] Dwelling

Beholders are recruited in the Pillar of Eyes.

[edit] Upgrading

Beholders can be upgraded to Evil Eyes for 30 gold per Beholder.