Baby Harp Seal Knight

Brave. The knight has advantage on saving throws against being Scared. 

Aura of Protection. Whenever the knight-paladin or a friendly creature within 10 feet of it must make a saving throw, the creature gains a +2 to the roll. The knight-paladin must be conscious to grant this bonus.

Pure. Cannot be [Charmed] or otherwise controlled by any creature with an Evil alignment.

Immeasurable Cuteness: Any creature able to see the Baby Harp Seal must make a DC 18 [Wisdom] saving throw or be charmed by the Baby Harp Seal. They cannot re-roll until they can no-longer see the Baby Harp Seal.

Aquatic: Can hold their breath for up to 30 minutes.

Great Weapon Fighting. When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Interception. When a creature you can see hits a target, other than you, within 5 feet of you with an attack, you can use your reaction to reduce the damage the target takes by 1d10 + your proficiency bonus (to a minimum of 0 damage). You must be wielding a shield or a simple or martial weapon to use this reaction.

Multitrack. The Knight Paladin makes two melee attacks.

Black Great sword (+3 Great sword) Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 30 (3d10 + 9) slashing damage. 

Heavy Crossbow. Ranged Weapon Attack: +3 to hit, range 100/400 ft., one target. Hit: 5 (1d10) piercing damage.

Tail Slap. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: +5 (1d10 + 3) [bludgeoning] damage. 

Leadership (Recharges after a Short or Long Rest). For 1 minute, the knight can utter a special command or warning whenever a nonhostile creature that it can see within 30 feet of it makes an attack roll or a saving throw. The creature can add a d4 to its roll provided it can hear and understand the knight. A creature can benefit from only one Leadership die at a time. This effect ends if the knight is incapacitated.

Call for Help. (Must have taken damage to use this ability) Any ally of the Baby Harp Seal within 100ft must make a DC 14 [Constitution] save or be compelled to go to the Baby Harp Seal's location, which they are made aware of,  and fight to protect it. Those who succeed the save are still aware of the danger and may choose to assist anyway.

Divine Smite

Starting at 2nd level, when you hit a creature with a melee weapon attack, you can expend one spell slot to deal radiant damage to the target, in addition to the weapon's damage. The extra damage is 2d8 for a 1st-level spell slot, plus 1d8 for each spell level higher than 1st, to a maximum of 5d8. The damage increases by 1d8 if the target is an undead or a fiend, to a maximum of 6d8.

Parry. The knight-paladin adds 2 to its AC against one melee attack that would hit it. To do so, the knight must see the attacker and be wielding a melee weapon.

Lay on Hands. The knight-paladin is able to reach one creature withing 5 feet, including itself, and you can touch that creature and draw divine power to restore up to 30 hit points to that creature.