- Heroes in Heroes 3

You can determine the level of a neutral creature by its quantity (10 or more = level 1, 8-10 = level 2, 5-7 = level 3, 4-5 = level 4, 3 = level 5, 2 = level 6, 1, rarely 2 = level 7 and higher).
Of course, it's easier to find Liches... Having a Dragon, finding (or rather, creating/upgrading) Wizards won't be difficult.