Note: All monster names are conjectured, since none of them are specifically named in the manual. However, Tower of Doom was originally planned as a licensed Advanced Dungeons & Dragons title, but was unfinished when Mattel Electronics was closed, and was then finished and released without the AD&D license by INTV Corp.
Given the inclusion of canonical AD&D monsters like the Beholder and Owlbear, it seems extremely likely that the monsters were modeled after creatures from the AD&D mythos, and they have been named accordingly in this guide.
Monsters with a speed of "Very fast" are faster than the player.
|Giant rat||Slow||10||Weak and relatively stupid. Will accept valueless items in barter, e.g. a boot.|
|Stirge||Very fast||10||Relatively weak, but dangerous to underpowered character classes like the Waif.|
|Skeleton||Slow||20||Relatively weak. Will accept valueless items in barter.|
|Giant stag beetle||Fast||40||Does low-to-medium damage. Small chance a successful hit against you will be abnormally high (about 3 yellow shields worth).|
|Axebeak||Average||80||Does low-to-medium damage.|
|Giant scorpion||Slow||160||Does medium damage. Small chance a successful hit against you will permanently reduce your HP (black bar).|
|Owlbear||Slow||320||Does high damage. This is the first monster that is notably challenging. Seems harder than the wraith (but slower).|
|Wraith||Very fast||640||Does medium-high damage. Extremely fast.|
|Hydra||Slow||1280||Does very high damage. This monster and all ones after it are extremely tough. Be prepared, or chip away with projectiles before hand to hand combat.|
|Beholder||Average||2560||Does very high damage.|
|Dragon||Slow||5120||Does very high damage.|
|Wizard||Fast||10240||Does very high damage.|