You can find some nice human-curated Halloween-themed Fediverse videos on this playlist:
馃巸 https://fedi.video/w/p/ddtnp1T5TCMxzsFDRs35e4
If you see an account or channel on the playlist that you want to follow from Mastodon, click on its name to see its profile page and then copy its address into your Mastodon search box (step-by-step instructions on how to do this at https://social.growyourown.services/@FediTips/115435794219496416).
You can also find lots more human-curated video playlists at https://fedi.video