What classification of aerial vehicle would a manned quadcopter or octocopter be? US here, if it makes a difference (w.r.t. FAA regulation, etc.).
There's a new upcoming class of aerial vehicles, similar to drones, however they are gigantic and they are manned -- that is, manned (piloted) quadcopters or octocopters like these ones.
I'm wondering what technical and/or legal classification(s) these types of vehicles would be considered to be. Any thoughts? Thanks in advance!
From 14 CFR 1.1:

Helicopter means a rotorcraft that, for its horizontal motion, depends principally on its engine-driven rotors.
Rotorcraft means a heavier-than-air aircraft that depends principally for its support in flight on the lift generated by one or more rotors.
Aircraft means a device that is used or intended to be used for flight in the air.

A manned quad- or octocopter seems to fit the definition for “helicopter”, assuming you mean the kind that have no fixed wing.