Excal-heim
Blood Frenzy. The wolf has advantage on melee attack rolls against any creature that doesn't have all its hit points.
Keen Hearing and Smell. The wolf has advantage on Wisdom (Perception) checks that rely on hearing or smell.
Multiattack. The wolf makes 2 claw attacks or 1 bite attack. Bite. Melee Weapon Attack: +5 to hit, reach 5 ft, one target. Hit: 11 2d6+4 piercing + 3 1d6 lightning + 3 1d6 cold damage. If the target is a creature, it must succeed on a DC 15 Strength saving throw or be knocked prone. Claw. Melee Weapon Attack: +5 to hit, reach 10 ft, one target. Hit: 7 1d6+4 slashing + 2 1d4 lightning + 2 1d4 cold damage. Cryostorm Howl(1/day). The wolf unleashes a howl and releases part of its electricity within a 10-foot-radius around itself. Each creature in the area must make a DC 12 Dexterity saving throw. On a fail, they take 7 2d6 lightning + 7 2d6 cold damage and are stunned until the start of their next turn.