Revision 1

Square Enix states that DRAGON QUEST MONSTERS: The Withered World holds more than 500 monster species, drawn both from the wider DRAGON QUEST series and from creatures new to this game. Every one of them is described by four properties: a family, a rank, a size, and a personality.

Families

There are eight families, which Square Enix illustrates with slimes and dragons. Seven of them have appeared in published material. Five have a confirmed English name; two more have been shown only in Japanese, and Square Enix has not published an English rendering for either.

The eighth family does not appear anywhere in the material published so far, in either language, including on the official monster listings. Its name is genuinely unknown rather than merely untranslated.

Ranks

Each monster sits at one of nine ranks, which Square Enix describes as running from G to X. Seven of those steps appear in published examples: G, F, E, D, C, B and A. The step between A and X has not been named, and no monster has been shown at rank X yet.

Rank is not a simple power level you outgrow. Synthesis reads rank directly: pushing a parent's Plus Value high enough can produce a child that outranks both of its parents, and one of the published worked examples pairs a rank G monster with a rank E monster to produce a rank D child. See Synthesis.

Sizes

Monsters are either small (S) or large (L). A large monster costs two of your four active party slots, but it carries more Traits than a small one and many large monsters act more than once per turn. Outside battle, size makes no difference: any monster can walk the field with you.

Personality

Personality varies between individuals of the same species, and it sets both the upper limits of a monster's attributes and how fast they grow. Two otherwise identical monsters can therefore develop quite differently. Items exist for changing a monster's personality, so the roll you get when you recruit one is not permanent. See Monster Growth and Talents.

Why there is no roster list here

The gap between the stated roster and the published roster is large. Square Enix has put out individual profiles for 23 monsters, each giving a family and a rank, and has published official English names for 17 monsters. Those two sets barely overlap, and together they cover a small fraction of a 500-plus roster.

A list assembled from that material would be a fragment presented as a catalog, and the obvious way to "finish" it would be to import names and data from earlier games in the series. That does not work here: this series reworks family assignments, rank scales, skill tables and synthesis charts with every entry, so older data is not evidence about this game. A roster will go up when there is a roster to publish.

What is confirmed and what is not