Hi Nathan,
Im currently constructing a mono black rogue deck based on cards from morningtide as well as some lowryn cards. The idea is to have small creatures such as prickly boggart and nighstshade stinger attack allowing me to pay prowl cards for cheap creatures and spells. Some creatures will boost the rest of the rogues while others will be discard effects. Intended for standard Please check it out and give me your advice!

Rogue Robbin'
18 Swamps

24 Creatures:
4x Prickly Boggart
4x Nightshade Stinger
4x Oona's blackgaurd
4x Oona's prowler
4x Stinkdrinkers Bandit
4x Earwig Squad

19Non-creature Spells
4x Morsel Theft
4x Cloak and DAgger
4x Thought Seize
4x Distress
2x BitterBlossom

Total: 61

14 SideBoard
4x Noggin Whack
4x Bad Moon
4x Frogtosser Banneret
2x BitterBlossom

 

I have to give you credit for a good deck list. The only obvious room for improvement would be to add Mutavault and some removal. Shriekmaw and Nameless Inversion ought to help keep the kithkin and elves where they belong (face down). Bitterblossom is definitely good enough to be a four-of. Cloak and Dagger and Morsel Theft disappointed me when I play-tested this deck, and I ended up cutting them. I have also tweaked your sideboard a bit.

 

From Behind.dec v1.1

28/12/20

4 Prickly Boggart

4 Nightshade Stinger

4 Oona’s Blackguard

4 Oona’s Prowler

4 Stinkdrinker Bandit

4 Shriekmaw

4 Earwig Squad

 

4 Thoughtseize

4 Nameless Inversion

4 Bitterblossom

 

4 Mutavault

16 Swamp

 

Sideboard:

4 Pithing Needle

4 Deathmark

4 Extirpate

3 Damnation