Thrummren

Lightning Absorption. Whenever the thrummren is subjected to lightning damage, it takes no damage and instead regains a number of hp equal to the lightning damage dealt.

Magic Resistance. The thrummren has advantage on saving throws against spells and other magical effects.

Magic Weapons. The thrummren's weapon attacks are magical.

Storm Hide. A creature that touches the thrummren or hits it with a melee attack while within 5 feet of it takes 7 (2d6) lightning damage. The thrummren can choose for its rider to not be affected by this trait.

Multiattack. The thrummren makes two attacks: one with its gore and one with its hooves.

Gore. Melee Weapon Attack: +9 to hit, reach 15 ft., one target. Hit: 24 (3d12 + 5) piercing damage plus 10 (3d6) lightning damage.

Hooves. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 14 (2d8 + 5) bludgeoning damage plus 10 (3d6) thunder damage.

Thunder Stomp (Recharge 5-6). The thrummren rears back and slams its front hooves into the ground. Each creature within 20 feet of the thrummren must make a DC 17 Strength saving throw. On a failure, a creature takes 35 (10d6) thunder damage, is pushed up to 10 feet away from the thrummren, and is deafened until the end of its next turn. On a success, a creature takes half the damage and isn't pushed or deafened.

Protect Rider. When the thrummren's rider is the target of an attack the thrummren can see, the thrummren can choose to become the target of the attack instead.