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.

Blossoming Defense

Target creature you control gets +2/+2 and gains hexproof until end of turn.

Forest

Ember-Eye Wolf

Haste
{1}{R}: Ember-Eye Wolf gets +2/+0 until end of turn.

Silverfur Partisan

Trample
Whenever a Wolf or Werewolf you control becomes the target of an instant or sorcery spell, create a 2/2 green Wolf creature token.

Nature's Way

Target creature you control gains vigilance and trample until end of turn. It deals damage equal to its power to target creature you don't control.

Neck Breaker

Attacking creatures you control get +1/+0 and have trample.
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Neck Breaker.

Breakneck Rider

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

Breakneck Rider // Neck Breaker

Spirit of the Hunt

Flash
When Spirit of the Hunt enters, each other creature you control that's a Wolf or a Werewolf gets +0/+3 until end of turn.

Mountain

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

Sinuous Predator

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

Kessig Prowler

Kessig Prowler // Sinuous Predator

Moonrise Intruder

Menace (This creature can't be blocked except by two or more creatures.)
At the beginning of each upkeep, if a player cast two or more spells last turn, transform Moonrise Intruder.

Village Messenger

Haste
At the beginning of each upkeep, if no spells were cast last turn, transform Village Messenger.

Village Messenger // Moonrise Intruder

Pack Guardian

Flash (You may cast this spell any time you could cast an instant.)
When Pack Guardian enters, you may discard a land card. If you do, create a 2/2 green Wolf creature token.