Beastly Kelpie Horse

Amphibious: The kelpie can breathe air and water.

Bonding. The steed can magically bond with one creature it can see, immediately after spending at least 1 hour observing that creature while within 30 feet of it. The bond lasts until the steed bonds with a different creature or until the bonded creature dies. While bonded, the steed and the bonded creature can communicate telepathically with each other at a distance of up to 100 feet.

llusory Appearance: The kelpie covers itself with a magical illusion that makes it look like a majestic white horse or an intimidating black steed. The illusion ends if the kelpie takes a bonus action to end it or if it dies.

The changes wrought by this effect fail to hold up to physical inspection. For example, the kelpie could appear to have a clean mane, but someone touching it would feel its wet kelp. Otherwise, a creature must take an action to visually inspect the illusion and succeed on a DC 15 Intelligence (Investigation) check to discern that the kelpie is disguised.

Fey Resistance. The Kelpie has advantage on saving throws against illusion magic and is immune to charm effects. Magic cannot put the Kelpie to sleep.

Sticky Skin. The Kelpie adheres to anything that touches it. A Huge or smaller creature adhered to the Kelpie is also grappled by it (escape DC 13). Ability checks made to escape this grapple have disadvantage.

Grappler. The Kelpie has advantage on attack rolls against any creature grappled by it.

Charge. If the Kelpie moves at least 20 feet straight toward a target and then hits it with a ram attack on the same turn, the target takes an extra 7 (2d6) bludgeoning damage. If the target is a creature, it must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the kelpie can make another attack with its hooves against it as a bonus action.

Weakness to Iron. when the Kelpie comes in contact with iron it deals 7 (2d6) fire damage and loses its reaction

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

Ram. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage.

Trample. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 13 (3d6+2) bludgeoning damage.

Fey Charm. The kelpie targets one humanoid or beast that it can see within 30 feet of it. If the target can see the kelpie, it must succeed on a DC 15 Wisdom saving throw or be magically charmed. The charmed creature regards the kelpie as desirable and must make every attempt to approach the kelpie. Although the target isn't under the kelpie's control, it takes the kelpie's requests or actions in the most favorable way it can.

Amphibious Rampage. The Kelpie while in water can use its bonus action to dash up to half its movement (swim speed).

Bite. Melee Weapon Attack:+6 to hit, reach 5 ft., 1 target. Hit: 9 (2d4 + 4) piercing damage. When within range, the Kelpie can whip it's head out in an attempt to bite.

Drown: When the kelpie succeeds in restraining a creature, it may plunge the creature under the water as a reaction. A creature may survive under the water for (1+Constitution modifier) rounds, (minimum of one). If the creature does not escape within its time, it falls unconscious and loses half its Hit Points every round. The drowning creature may attempt to escape as an action by making a DC 15 Strength saving throw. Should the kelpie be attacked or move, the restrained condition and drowning attempt ends.

Shove. If the Kelpie is targeted by a melee attack it may use its reaction to force the attacker to make a (DC 17) strength saving throw or fall subject to the Sticky Skin trait

Chase. If a target chooses to retreat, a Kelpie may choose to chase after as a reaction. Target must succeed on a (DC 10) DEX saving throw or take 10 (2d8+1) bludgeoning damage.