Monsters in the Halls of Arden Vul.
According to Zushekt they are probably(?) no longer there.

Huzzah! learned at the Stunned Acolyte that the hoppers are formally known as Heqeti. According to the rumors he heard, they come in various shapes, some of which are more bestial and some of which are more humanoid. The latter, although physically weaker, are magically adept. All are inimical to humankind.