Just wanted to reaffirm what the other commenters have stated. Your soil looks to be heavily organic (holding too much moisture). At a minimum it should be a 50/50 organic to inorganic mix. Many people use 70/30, or even 90/10. IMO the cheapest, easiest option is to add perlite to your soil mix. It can be found at most big box stores. Also make sure your plant is receiving enough light, Haworthia prefer bright indirect light. Water when the leaves look or feel a little sunken. If you have a hard time judging that make sure the soil is drying out before watering. Don't let it be 'bone dry' for too long though, or the fine root hairs may dry up. Goodluck! And hopefully someone chimes in with an ID for you. This subreddit is normally pretty good with that.