Probably should've led with this since it predates Ultraman

#1 Gomess - modified Godzilla suit
#1b Litra - modified Rodan puppet
#2 Goro - modified King Kong suit
#3 Namegon - Mothra's crawling mechanism with Varan roar
#5 Peguila - Maguma roar
#6 Kai Dragon - Manda puppet
#7 Gorgos - King Kong + Godzilla roars
#12 Larugeus - modified Litra puppet
#14 Peguila - Varan + Godzilla 1954 roars
#18 Pagos - modified Baragon suit with Varan/Godzilla roar
#19 Kemurian - altered Matango laugh
#21 Bostang - modified Clapton puppet
#23 Sudar - reused Oodako tentacle + King Kong vs Godzilla stock footage
#27 Todora - Maguma suit