Blood tiles will spawn in three locations:
The first and most widely known is a random evil mage camp just outside the mouth of the valley to Wrong. This spawn still occurs to this day however it is very seldom. Some people will camp the area and continuously kill off the gypsie/sheep/wolf spawns to try and "hurry" the chances of the evil mage spawn. Whether this _actually_ works is anyone's guess. I've caught the evil mage camp a couple times.

The second and pretty much forgotten is at the small peak in the road leading east, away from the Compassion desert crossroads. On nearly all shards and in both facets, this point is covered over by a house, blocking the spawn.

The third and the most "legendary" is the "Dark Tower" north from the southeast corner of the lost lands. There is a large, empty clearing where a classic large tower will spawn with a party of orcs inside. On the rooftop of the tower is a stone ankh, with the 2 blood tiles to either side. The rate of this spawn are estimated to be about once or twice a year.

All spawning blood tiles are on the same 10 minute timer as anything else from a camp spawn. Should you ever see any of the spawns and be fortunate enought to grab one or both of the tiles, you must cross server boundaries to a bank on a different server than the originating spawn site, place the tiles in the bank and wait until after shard maintenance.

Other random spawns of interest that still occur:
Every now & again, a cage with hanging skeletons and an NPC will spawn outside the entrance to Despise. There will be a table with food, a chair, and possibly a couple brigands or skeletons as well.

In place of the evil mage camp outside of Wrong, there will sometimes be a friendly mage camp with nothing to be taken. This spawn tends to upset people hoping for the evil mage camp.

There use to be many more such unique spawns, however most have been covered over with houses or simply turned off by EA.