It’s that time of the year for spooky stuff. I used this one in a session a couple weeks back to great effect. Having the Specter first act invisibly will put the players on edge. I combined the design principles of LevelUp 5e’s Monstrous Menagerie, the Legendary Bestiary, and Matt Colville to create the Inspired Specter.

Combat.
The specter will always start combat while invisible first throwing objects or even trying to throw the PCs themselves. It will become visible when it first uses its life drain attack. The specter will use its legendary actions to move around the battlefield and focus it’s hatred on those doing the most damage to it.
Sources of Inspiration
Matt Colville’s Action-Oriented Monsters – https://www.youtube.com/watch?v=y_zl8WWaSyI
Legendary Bestiary: Legendary Actions for Low-Level Monsters – https://www.drivethrurpg.com/product/307926/Legendary-Bestiary-Legendary-Actions-for-LowLevel-Monsters
LevelUp 5e Monstrous Menagerie – https://enpublishingrpg.com/collections/level-up-advanced-5th-edition-a5e/products/level-up-monstrous-menagerie-a5e?variant=41366519775426
Drop your requests for ttrpg homebrew magic items, monsters, or random tables in the comments below.