Do the bosses spawn at any time or only during server save?

Question

How does the boss spawn of the bosses that spawn all over tibia work? Can they appear at any time? Or is it at server save or floor reset?

Answer 1

Some bosses have random respawn, the best way to know when a boss is about to respawn is using tibiabosses.com

That show you a estimated time to the next spawn of the boss.

Answer 2

It depends on which boss you mean of course but bosses with random spawn can appear randomly. From my own experience I noticed that very often bosses appear after reset floor (maybe not exactly with reset floor but soon after it took place), but I can not say about any rule in this case.