Fen Stalker

Fen Stalker has fear as long as you control no untapped lands. (It can't be blocked except by artifact creatures and/or black creatures.)

Nightstalker Engine

Nightstalker Engine's power is equal to the number of creature cards in your graveyard.

Shimian Night Stalker

{B}, {T}: All damage that would be dealt to you this turn by target attacking creature is dealt to Shimian Night Stalker instead.

Return of the Nightstalkers

Return all Nightstalker permanent cards from your graveyard to the battlefield. Then destroy all Swamps you control.

Breathstealer

{B}: Breathstealer gets +1/-1 until end of turn.

Urborg Panther

{B}, Sacrifice Urborg Panther: Destroy target creature blocking Urborg Panther.
Sacrifice a creature named Feral Shadow, a creature named Breathstealer, and Urborg Panther: Search your library for a card named Spirit of the Night, put that card onto the battlefield, then shuffle.

Prowling Nightstalker

Prowling Nightstalker can't be blocked except by black creatures.

Brutal Nightstalker

When Brutal Nightstalker enters, you may have target opponent discard a card.

Spirit of the Night

Flying, trample, haste, protection from black
Spirit of the Night has first strike as long as it's attacking.

Feral Shadow

Predatory Nightstalker

When Predatory Nightstalker enters, you may have target opponent sacrifice a creature of their choice.

Lurking Nightstalker

Whenever Lurking Nightstalker attacks, it gets +2/+0 until end of turn.

Abyssal Nightstalker

Whenever Abyssal Nightstalker attacks and isn't blocked, defending player discards a card.

Raiding Nightstalker

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)