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

Moonmist

Transform all Humans. Prevent all combat damage that would be dealt this turn by creatures other than Werewolves and Wolves. (Only double-faced cards can be transformed.)

Ulrich, Uncontested Alpha

Whenever this creature transforms into Ulrich, Uncontested Alpha, you may have it fight target non-Werewolf creature you don't control.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Ulrich, Uncontested Alpha.

Ulrich of the Krallenhorde

Whenever this creature enters or transforms into Ulrich of the Krallenhorde, target creature gets +4/+4 until end of turn.
At the beginning of each upkeep, if no spells were cast last turn, transform Ulrich of the Krallenhorde.

Ulrich of the Krallenhorde // Ulrich, Uncontested Alpha

Kazandu Refuge

Kazandu Refuge enters tapped.
When Kazandu Refuge enters, you gain 1 life.
{T}: Add {R} or {G}.

Merciless Predator

At the beginning of each upkeep, if a player cast two or more spells last turn, transform Merciless Predator.

Reckless Waif

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

Reckless Waif // Merciless Predator

Mountain

Full Moon's Rise

Werewolf creatures you control get +1/+0 and have trample.
Sacrifice Full Moon's Rise: Regenerate all Werewolf creatures you control.

Howlpack Alpha

Each other creature you control that's a Werewolf or a Wolf gets +1/+1.
At the beginning of your end step, create a 2/2 green Wolf creature token.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Howlpack Alpha.

Mayor of Avabruck

Other Human creatures you control get +1/+1.
At the beginning of each upkeep, if no spells were cast last turn, transform Mayor of Avabruck.

Mayor of Avabruck // Howlpack Alpha

Rugged Highlands

Rugged Highlands enters tapped.
When Rugged Highlands enters, you gain 1 life.
{T}: Add {R} or {G}.

Wildblood Pack

Trample
Attacking creatures you control get +3/+0.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Wildblood Pack.

Instigator Gang

Attacking creatures you control get +1/+0.
At the beginning of each upkeep, if no spells were cast last turn, transform Instigator Gang.

Instigator Gang // Wildblood Pack

Forest

Howlpack Resurgence

Flash (You may cast this spell any time you could cast an instant.)
Each creature you control that's a Wolf or a Werewolf gets +1/+1 and has trample.

Moonlight Hunt

Choose target creature you don't control. Each creature you control that's a Wolf or a Werewolf deals damage equal to its power to that creature.

Sinuous Predator

Sinuous Predator can't be blocked by more than one creature.

Kessig Prowler

Kessig Prowler // Sinuous Predator

Immerwolf

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Each other creature you control that's a Wolf or a Werewolf gets +1/+1.
Non-Human Werewolves you control can't transform.