Here is the complete listing of all creatures' genus (the creature type). This listing is often excellent for lord cards, such as a Goblin Lord that will effect a theme deck based on goblins. It's also note worthy to mention that gender has no effect (such as brother/sister), as well as quantity (elf is the same as elves; this was fixed in Classic Edition). This does not have creature generators. However, thanks to Classic Edition this does now include creatures which "count as a ...". Some of these creature types will show you that during the early days of Magic: The Gathering, Wizards of the Coast's Research and Development (R&D) team were obviously still working out their problems . . .
There are a total of 340 creature types currently in existence (as of Saviors of Kamigawa). Over 175 of these creature types appear only on one card.