Wing Shredder

Reach
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Bird Admirer

Reach
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Bird Admirer // Wing Shredder

Fangblade Eviscerator

{1}{R}: Fangblade Eviscerator gets +1/+0 and gains first strike until end of turn.
{4}{R}: Creatures you control get +2/+0 until end of turn.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Fangblade Brigand

{1}{R}: Fangblade Brigand gets +1/+0 and gains first strike until end of turn.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Fangblade Brigand // Fangblade Eviscerator

Nightfall Predator

{R}, {T}: Nightfall Predator fights target creature. (Each deals damage equal to its power to the other.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Nightfall Predator.

Daybreak Ranger

{T}: Daybreak Ranger deals 2 damage to target creature with flying.
At the beginning of each upkeep, if no spells were cast last turn, transform Daybreak Ranger.

Daybreak Ranger // Nightfall Predator

Krallenhorde Howler

Creature spells you cast cost {1} less to cast.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Krallenhorde Howler.

Duskwatch Recruiter

{2}{G}: Look at the top three cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in any order.
At the beginning of each upkeep, if no spells were cast last turn, transform Duskwatch Recruiter.

Duskwatch Recruiter // Krallenhorde Howler

Gatstaf Howler

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Gatstaf Howler.

Gatstaf Shepherd

At the beginning of each upkeep, if no spells were cast last turn, transform Gatstaf Shepherd.

Gatstaf Shepherd // Gatstaf Howler

Tovolar, the Midnight Scourge

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
{X}{R}{G}: Target Wolf or Werewolf you control gets +X/+0 and gains trample until end of turn.
Nightbound

Tovolar, Dire Overlord

Whenever a Wolf or Werewolf you control deals combat damage to a player, draw a card.
At the beginning of your upkeep, if you control three or more Wolves and/or Werewolves, it becomes night. Then transform any number of Human Werewolves you control.
Daybound

Tovolar, Dire Overlord // Tovolar, the Midnight Scourge

Savage Packmate

Trample
Other creatures you control get +1/+0.
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Child of the Pack

{2}{R}{G}: Create a 2/2 green Wolf creature token.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)