I keep coming across new and different character generators and I think it'd be useful to maintain a list! If anyone had any they like, feel free to post here.
picrew.com
artflow.ai
https://na.leagueoflegends.com/en/featured/events/avatar-creator#/
In addition to these, there's also midjourney and other AI art generators that can get you character portraits.
Edit: We've decided not to encourage the use of AI art, and stop using it ourselves for NPC portraits. That doesn't mean we'll necessarily be redoing all old NPC portraits, but just that going forward, if we decide that something needs to be made more artistic and customized, we will search for a sentient artist. If players want to use AI artwork for character portraits, we aren't going to enforce any rules related to this or even make any formal requests. However, we really don't want players to be using AI writing generators for roleplay. (We're not going to police this either, as that would be a nightmare, but it's a seriously stated request.)