There are those who, in life, lead lives so devoid of pleasure that the only enjoyment they find is in scolding and rebuking others for failing to live up to a imagined (though deeply-believed) system of ethics or morality. These people might be actual spinster schoolmarms, but they might as easily be anhedonic prelates, finger-wagging censors, or even jaded sybarites who can now only find joy in judging the actions of others.
When such an individual dies there is a fleeting chance that they will return as an undead creature bent on continuing to admonish and chide the living.
Move: 120' (40') AC: 14 HD: 2 Attacks: 2 (AB +2) Dam: 1d4 (shaking fists) Mor: 12
Special Abilities: Castigate – an Undead Schoolmarm can verbally reprimand one living being per round. The victim of this attack must make a successful saving throw. If failed, a lawful character takes the criticism to heart and suffers a -2 penalty on all actions until the Schoolmarm is defeated; a neutral character finds themselves suffering from the effects of a slow spell as they attempt to follow the Schoolmarm's emotional lecturing; a chaotic character loses their next action from laughing at the Schoolmarm's silly reproach. Undead.