Grrrrr, Growl, Grumble, Gore, Ghost, Green, Ghastly, Goblin, Gobble.
That's most likely not all of them.
Ghost, ghoul... etc.
ghostghoulgoblingoregrotesque
"Halloween Words" Is very broad, but I will do my best.MonsterM&MsMaskMurderMagic3 MusketeersMilkywayMilkduds
Nightmare and ninja costume are Halloween words. They begin with the letter n.
nasty
qweze
There are several Halloween words that start with the letter S. They are spooky, scary, strange, supernatural, sweets, superstition, and startling.
Pumpkin
skeletonscarecrowscare, scaryslimespiritssqueeksscreams
pumpkin pirate
xray costume
FUN lol