Shapechanger. The wolf can use its action to polymorph into a beast form that resembles a raven (speed 10 ft. fly 40 ft.), a huntsmen spider (40 ft., climb 40 ft.), or an adder (40 ft., swim 40 ft.), or back into its true form. Its statistics are the same in each form, except for the speed changes noted. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.
Magic Resistance. The wolf has advantage on saving throws against spells and other magical effects.
Pack Tactics. The wolf has advantage on attacks while the target is within 5ft of one of its allies.
Multiattack. The familiar makes 2 attacks consisting of any combination of Bite or Slam attacks as apart of its attack action. It may replace either its attack with Growl.
Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 4) piercing damage, and the target must succeed on a DC 15 Constitution saving throw or take 5 (2d4) poison damage and become poisoned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 6 (1d8 + 8) bludgeoning damage, and the target must succeed on a DC 15 Strength saving throw or become prone.
Growl (1/Day). One creature of the wolf's choice within 20 feet of it must succeed on a DC 15 Wisdom saving throw or be frightened for 1 minute. The target can repeat the saving throw at the end of each of its turns, with disadvantage if the wolf is within line of sight, ending the effect on itself on a success.
Chromatic Bane. The familiar can mark an enemy hit by one of its attacks. The creature makes a DC 15 Dexterity save, On a failed save the target is highlighted by an aura similar to the familiars. While the target is highlighted attack rolls aginst it have advantage. The familiar also knows the exact location of the marked target even if it is invisible.