Diving straight in, the Introduction compares 'traditional' and more 'experimental' styles of role-playing, with a strong case for the 'traditional' style being timeless and enjoyable by successive generations of gamers... but that while good plot design, innovative situations and novel traps will keep players on their toes, the classic monsters are so well-known even beyond role-players that reactions to them are predicatable and dull. To regain the sense of wonder - and of danger - that a monster encounter ought to provide, this book is intended to aid the referee in providing new, even unique, monsters without the need for being a professional monster designer!
The method proposed - as indicated by the title - is based on random tables, but from the outset the referee is encouraged to allow his own ideas to take priority, using the tables as stimulus rather than a straitjacket. An interesting note is that creatures need not necessarily be balanced to party strength, provided the monster does not have to be defeated in face-to-face combat for mission objectives to be achieved, it is quite all right for the party to flee in terror from an overwhelming opponent!
Beginning with a run-down of the essential characteristics that will need to be determined, there are then a selection of tables to help decide everything from body shape to method of locomotion, how it fights and even its distinctive features. Strict adherence to die rolls can result in mighty odd creatures - but if the result is not quite right, go ahead and change anything you wish. You can even determine combat strategy randomly, if the creature's design does not make one obvious - even if you choose not to roll on any of the tables, just reading them can start spawning ideas for that next show-stopping monster! The book rounds out with suggestions for drawing all your ideas and rolled results into a coherent whole, and then ways in which it can be presented effectively to your players and their characters.
While presented as 'systemless' the book is actually geared towards the general outlook of Dungeons & Dragons, although it doesn't matter which edition you play. If you use a different fantasy ruleset, you may need to develop different information for monsters but these tables will at least help you to devise the basic concept of your monster even if you then need to build the final design to suit the rule mechanics of your choice. Overall, if you want to go beyond published monsters, this is a good book for ideas if not complete creatures!
Random Esoteric Creature Generator