So in my world, I do plan on running some homebrew elements to make the game more fun and interesting. For those who do not know what I mean when I say "homebrew" basically they involve anything about the game whether it be items, events, NPCs, classes, races, monsters, etc that are not official. They are made up of the DnD community and some of these homebrewers have gotten to the point where they can be considered a sort of pseudo-homebrew where they're almost official but not exactly like Matt Mercer's Gunslinger and Blood Hunter. I have come up with some homebrews of my own and not just what I've found but to quickly explain the link above, the Giants have trained their citizens in the ways of combat with these mystic runes, the race the Giants rule over are related to them but not exactly like them, a group of people called Goliaths. These Goliaths then took these practices and taught them to the Dwarves due to the close relationship these races have together being neighbors within the mountains.
As for my homebrews, I will only speak of one otherwise you'd be reading an essay. My homebrew creature is a giant spider that makes it's home on the ocean, sailing across it upon an iceberg like device but is made entirely of its webbing. It naturally can walk across water and attacks any ships it sees. They are a very dangerous threat as when they are left unchecked, the nests get bigger and bigger until they form what are called "Silk Islands" which can host dozens of large spiders and thousands of egg sacs. They are sought after due to their very rare webbing that is used to make fine clothing and magical life vests as the properties of this silk make it so that it can never be submerged in any liquid as it will immediately go back up to the surface. Mechanically, it gives the person wearing such an item the passive ability Walk on Water spell.