Let’s come up with a monster.

Maiden on a Pegasus - an elven demigoddess
health 120, damage 20-32, attack 24, defense 22
speed 9, initiative 16, price - 2000
Immune to magic, flight. It could also be made so that when she stands next to a mage, he cannot cast spells.

Incubus - a dark spirit capable of paralyzing an enemy with a scream, fast speed (6-7).

Charioteer - level 7, archer, mechanism, no penalty when close, high speed (7-8), but average initiative (8-10).

Nomad - horse archer - marauder

Added 4 minutes ago
The charioteer has about 150 health.

Added 1 minute ago
Not Undead, but Angel of Death.

Added 4 minutes ago
Angel of Death - a red version of the Herald, only with wings and level 7. It has the ability to inflict a deadly blow and poisons everyone around it.