Board Thread:Questions and Answers/@comment-12.249.147.238-20140322181453/@comment-24851346-20140515220851

I think we can at least make some rough comparisons.

I doub any are 'that' large, maybe two or three, four tops larger than the average tall person.

Elves probably are roughly similar to Humans, maybe a little taller and slimmer.

Many monsters are explicitly said to have a childlike body, such as the Alice, so same variances in height, weight, etc. there.

Some monsters don't need muscles for their strength, so a Minataur would have the extra mass needed for her strength, a goblin wouldn't.

Some are at least appear bigger than others, I'd say a Kraken is usually bigger than a Scylla.

I think the smaller ones, like Fairies and the like, are supposed to be a little bigger than the size of your hand.

Some species have more magically inclined flight, so a Succubus probably weighs more with a smaller wingspan than do Harpies. A couple who levitate might also be lighter as a result.

Other monsters are made of different materials than Humans, so Sylphs, and Ignis' weigh much less than humans, Undines, and Gnomes probably a little more. Slimes are mostly water too, and can vary their size and shape, so I bet that throws off the balance.

I bet most plantgirls would be lighter, save for maybe dryads, who aren't so much part tree, as attached to one.

Certain Beastmen you could probably split the difference. Take the height/weght of a Centaur, minuse the neck, and add it to the height/weight of a human women, minus the legs.

Also the Manga Monster Musume, which is pretty similar, is pretty good in regards to the biology of the girls, such as indirectly answering the Mermaid Problem. For instance, it mentions in a profile for Arachne that the Spider Half is pretty light compared to it's size. So she's still heavy for a human, but pretty light for a half-spider, about half again as heavy as a normal person.