Musschrott's Bestiarium was an immensely popular site devoted to Tibia's monsters. First launched sometime in Alpha 3 under http://privat.schlund.de/musschrott/tibia/bestiarium.html which now redirects, the site was incomplete in its early forms. We only have the last update before the site location was changed, so the earlier renditions do not exist. This version is the early days of the Beta 4 update, with the Daemon exp still a bit of a mystery and the Dragon exp still 700. Also, we know the Beholder dropped a Mastermind Shield at the time, but this was not known during this version of the site.
Sometime between the end of 1998 and early 1999 the site changed hosts to http://www.mordor.ch/musschrott/Bestiarium/. In this version we see the site finished with more details about Tibia's strong monsters, as the Beholder is shown to drop Mastermind Shields and the Daemon is now known to drop the rare Emerald. Also changed is the exp of the dragon from 700 exp to 500 exp, indicating that this version is after Beta 4.1 (June 5th, 1998). Oddly the bestiarium list exists and is credited on Ralgars site with a different version were the information is improved, the Daemon has his proper 1500 exp rate, and the Beholder is removed from the game. You can find this version here (http://www.geocities.com/TimesSquare/Alley/5584/tibia/infomon.html). The beholder was removed from the game late 1998 to early 1999 so this list is from that period. It seems likely that at some point Musschrott stopped updating his website and Ralgar started maintaining his own version of the monster list, stopping when the site was retired before the beta 5 update.