Alicorn

Legendary Resistance (3/Day). If the alicorn fails a saving throw, it can choose to succeed instead.  

Charge. If the alicorn moves up to 20 feet straight forward and then uses it's horn attack the attack does an extra 2d6 damage (included in the attack). In addition the target must succeed in a DC 18 strength saving throw or be knocked prone. 

Innate Spellcasting. The alicorn's innate spellcasting ability is charisma (spell save DC 17). The alicorn can innately cast the following spell requiring no material components.

At Will: Detect Evil and Good, Druidcraft, Pass Without Trace

2/Day each: Calm Emotions, Dispel Evil and Good, Entangle, Barkskin 

Magic Immunity. The alicorn can't be physically harmed by magic.

Magic Weapons. The alicorn's weapon attacks count a magical. 

Multiattack. The alicorn makes 3 attacks: 1 with it's hooves and 2 with it's horn.

Hooves. Melee Weapon Attack: +17 to hit, reach 5ft., one target. Hit: (5d10+10 bologoning damage). And Target must succeed a DC 20 strength saving throw or be knocked pone. 

Horn. Melee Weapon Attack: +17 to hit,  reach 8ft., one target. Hit: (5d6+10 piercing damage) or (7d6+20 piercing damage) with charge attack and target must succeed DC 18 strength saving throw or be knocked prone with charge attack.

Healing Touch (5/Day). The alicorn magically touches a creature with it's horn. The target regains 15 hit points and is cured of any conditions or diseases it had.

Teleport (2/Day). The alicorn teleports itself and up to four other creature and magically teleports them up to one mile away from where they were. 

Mystical Horn (1/Day). The alicorn shoots a beam of bright light from it's horn at one creature doing one of the following:

• The alicorn heals one creature to it's maximum hit points (it can do this to it's self to). 
• The alicorn deducts 1/4 of the targets current hit points.

Resurrection. If the alicorn uses all of it's legendary actions, if it drops to zero hit points, it can go to one instead. 

Legendary Actions. The alicorn can make 3 legendary actions on it's turn and regains all of them on it's next turn.

Hooves. The alicorn makes 1 hooves attack.

Shimmering Shield. The alicorn makes a glowing shield that it summons from it's hooves. It can place the shield around any creature within 60 feet of it (including it's self) and for 3 turns has a +3 to it's AC and is immune to the magic missile spell.

Heal Self (Costs 2 Actions). The alicorn makes it self heal 20 hit points.