What counts as "humanoid" for the target of the Enlarge Person spell?

Question

I know that similar versions of this question have been asked, even by me.

The line in question of the enlarge person spell says:

Target one humanoid creature

The glossary/common terms doesn't include this term. Nor does the spell itself state what a humanoid creature is. Is it a creature in a similar shape as a human, or possessing the humanoid subtype?

I ask because earth elementals are described as:

This hulking, roughly humanoid creature of dirt and stone explodes up from the earth, faceless save for two glowing gemstone eyes.

Thus, an earth elemental is humanoid in form but not type. Does the spell work on things with head(s), arm(s), leg(s), and a torso?

Answer 1

Enlarge person refers to the Humanoid creature type. Only creatures of that type can be targeted with that spell.¹ Creatures of any other type—aberration, animal, construct, dragon, fey, monstrous humanoid, ooze, outsider, plant, undead, or vermin—are not eligible for that spell. This would include earth elementals, as they are outsiders, not humanoids. Being “roughly humanoid in shape,” even being perfectly humanoid in shape (as, for example, a doppelganger might well be), is not relevant—only the creature type is.

1. _{Barring special cases like the spell sharing of animal companions}