I & II:

William Atherton (Walter Peck)
Michael Ensign (Hotel Manager)



Billy Bryan (Stay Puft)
Mark B. Wilson (Slimer)



Ernie Hudson (Winston Zeddmore)



Slavitza Jovan (Gozer)



Jennifer Runyon (Female Student)



Sigourney Weaver (Dana Barrett)



Legacy (Afterlife):

Mckenna Grace (Phoebe)
Logan Kim (Podcast)
Finn Wolfhard (Trevor)