Nicholas Holmes

as 1950s Young Mack's Dad

as Ryan

as Kid #2

as Young Lassie

as Young Max

as Noah

as Justin

as Dooley

as Professor Dixon

as Young Boy

as Young Norman

as Young Johnny

as Young Frank

as Bill (voice)

as Joel Hynek

as Hudson Harper (voice)

as Frederick

as Andy Landry

as Ernest

as Hudson Harper (voice)