Dragon Quest III/WMG

The elven shopkeepers aren't fooled by ANY shapeshifting; they just take advantage of it.
When you have the Change Staff, the elves aren't fooled by your shapeshifting -- if you try talking to them in different forms, they bluntly announce that they can see right through your illusions before repeating their normal lines. Yet if you shift into a proper, non-human or monster form, the shopkeepers won't claim that they can tell who you are -- they just welcome you to their shop. But just because they don't state it doesn't mean it doesn't still hold true. They're just pretending to be fooled so that they can do business with you. Human or not, your money's still good. The only reason they won't sell to you normally is the current Elf Queen's hatred of humans and fondness for Disproportionate Retribution.

Loto is the female canon name, Erdrick is the male canon name.
Just like Black/Touka/Hilbert and White/Touyo/Hilda.