The more I think about it, the more I wanna give these a bit "culture" they might mingle with the normal population by day, covering their bodies and faces in thick robes and veils. Sniffing out conflicts and vicious rivalries.

They use the treasure they've accumulated from burial sites, as well as their many years of gathering knowledge to gain influence and seed rumors in towns, increasing tension between factions until it escalates into open violent conflict, war!

When the dust settles, they move in to gather up the dead and have a magnificent dreadful feast. 

Quote from Xidien >>

The more I think about it, the more I wanna give these a bit "culture" they might mingle with the normal population by day, covering their bodies and faces in thick robes and veils. Sniffing out conflicts and vicious rivalries.

They use the treasure they've accumulated from burial sites, as well as their many years of gathering knowledge to gain influence and seed rumors in towns, increasing tension between factions until it escalates into open violent conflict, war!

When the dust settles, they move in to gather up the dead and have a magnificent dreadful feast. 

 That’s consistent with the lore around them, they are intelligent undead after all (I’d add in strong smelling herbs and perfumes to cover their scent).

Unlike vampires, who target rulers and well-connected with their manipulations, ghouls would likely work at the street level, subverting the peace from bellow.

that is a banshee

Doo ont attack theese in the icebound axeholm quest! DO NOT! Especially not while they are in a bathtub.

Quote from RaulSilvertoung >>

Doo ont attack theese in the icebound axeholm quest! DO NOT! Especially not while they are in a bathtub.

My playere may be doing the Axeholm quest next week so I feel like I need to hear the story behind this.

According to the table in the DMG, these things are CR 1/4, not Cr 1. Even with the paralyzing claws, these things still feel really weak, especially as the saving throw to resist the paralysis is only DC 10, and the target can repeat the save at the end of its turns.

Quote from haldir77 >>

I think in D&D lore, the first ghoul is or was a elf. (Lord Doresain or something like that)

 Yep.

Quote from Bragnak >>

Hello internet, help me

Do ghouls need to breathe air to survive?

 No. They are undead.

Quote from Dr_Frederick >>

Quote from Xidien >>

The more I think about it, the more I wanna give these a bit "culture" they might mingle with the normal population by day, covering their bodies and faces in thick robes and veils. Sniffing out conflicts and vicious rivalries.

They use the treasure they've accumulated from burial sites, as well as their many years of gathering knowledge to gain influence and seed rumors in towns, increasing tension between factions until it escalates into open violent conflict, war!

When the dust settles, they move in to gather up the dead and have a magnificent dreadful feast. 

 That’s consistent with the lore around them, they are intelligent undead after all (I’d add in strong smelling herbs and perfumes to cover their scent).

Unlike vampires, who target rulers and well-connected with their manipulations, ghouls would likely work at the street level, subverting the peace from bellow.

 They are intelligent, but as much so as an orc, which isn’t much. Technically ghouls and ghasts don’t rot too, so they wouldn’t have much of a problem with smell.

Quote from bobsobthegreat >>

that is a banshee

 What is?

Quote from legolasgreenleaf333 >>

According to the table in the DMG, these things are CR 1/4, not Cr 1. Even with the paralyzing claws, these things still feel really weak, especially as the saving throw to resist the paralysis is only DC 10, and the target can repeat the save at the end of its turns.

 Definitely true, but 2d4+2 isn't insignificant for lower-level characters. Also, these things are one of the only monsters which are going to attack a downed character without seeing them go down and get back up.

Quote from Bragnak >>

Hello internet, help me

Do ghouls need to breathe air to survive?

 yes

The Elves forgave him in his time of need when the evil god (gods) abandoned him. The first ghoul was an elf that decided he wanted to eat his own kind. Thus elves are immune.

Love it

orcs ain't quite that smart though, and their personality is shattered when they become a ghoul.

I am making a dungeon with Violet Fungus as a defense. Could I make the ghouls immune to necrotic damage, therefore making them immune to the Violet Fungus? I would also do the same thing with wights and wraiths. 

Are Drow immune to the paralysis? 

lore

Imagine how derailing a party of all elves would be to a published adventure that's supposed to have an encounter with ghouls.  Actually, that is easily remedied.  You would know if everyone in the party was playing an elf, and you could easily swap out the "ghouls" for ghasts or zombies.