The deathworm horns can be used in place of rhino horns

Use before killing lots of baby gigas lots of xp

You can get black pearls from squids and lobster things in the ocean.

Use to tame the rainbow centipede in caves and on scorched earth

Use it before completing swamp or yeti cave for extra xp

Use it before birthing/taming a reaper

Use on reaper Queens when you get the embryo

Unsure if this works and currently no way to test it but take a dump at a toilet eat this and finds a 4x explorer note for most exp ever?

Use it before trophy room pursuit(mobile only)

for taming an arthropluera this is the item you need to craft since it likes only take 1 at any level (if your on mobile it takes 1 for 300 and 450 for hard and brutal difficulty players)