Curse of Strahd: Potions is a one page pay what you want pdf on the Dungeon Masters Guild. It presents 7 Ravenloft themed potions. The powers provided by these concoctions often come at a price. They are as follows:
Moon Blood - You blood becomes acidic to vampires and undead that decide to bite you.
Wolf Eye's - You gain superior darkvision and sunlight sensitivity while under the effects of this potion.
Gallows Ichor - Weapons coated in this black ichor overcome damage reduction
Vistani Elixir - You gain advantage on all rolls for a few minutes and disadvantage on all rolls for a few days.
Corpseworm - This potion contains a centipede like creature that allows you to speak with a dead corpse, though after a few days a swarm of centipedes erupts from the corpse's mouth.
Morninglord's Tears - This potion can cure Lycanthrope from one that has not yet transformed, though doing ages the drinker.
Vial of Mist - This potion creates a 20ft sphere of mist.
These are all really cool and add a nice bit of flavor to Curse of Strahd. Pick it up and pass the creator a few silvers.