  An arbitrary outward cuspidal domain is shown to be bi-Lipschitz equivalent
to a Lipschitz outward cuspidal domain via a global transformation. This allows
us to extend earlier Sobolev extension results on Lipschitz outward cuspidal
domains from the work of Maz'ya and Poborchi to arbitrary outward cuspidal
domains. We also establish a limit case of extension results on outward
cuspidal domains.
