Blood Harvest Scarecrow

False Appearance. While the scarecrow remains motionless, it is indistinguishable from an ordinary, inanimate scarecrow.

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

Multiattack: The Scarecrow makes two Scythe attacks. It can use its Life Drain in place of one Scythe attacks 

Action Melee Attack. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 8 (1d8 + 4) slashing damage.  If the target is a creature, it must succeed on a DC 11 Wisdom saving throw or be frightened until the end of the scarecrow’s next turn.

Life Drain: Melee Weapon Attack: +9 to hit, reach 10 ft., one creature. Hit: 7 (1d6 + 4) necrotic damage. The target must succeed on a DC 13 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a Long Rest. The target dies if this effect reduces its hit point maximum to 0.

Down the rabbit hole. As long as the scarecrow is in a field used for growing crops, it may use its action to disengage by sinking into the ground and reappear instantly in an empty space within 30 feet

Terrifying Shriek.  The scarecrow targets one creature it can see within 30 feet of it. If the target can see the scarecrow, the target must succeed on a DC 17  Wisdom saving throw or be magically frightened until the end of the scarecrow’s next turn. The frightened target is paralyzed. Any creatures other than the target within 10 feet and can hear the shriek of the scarecrow must make a DC 15 wisdom saving throw or be frightened for one minute 

Can take 3 Legendary Actions, choosing from the options below. Only one legendary action can be used at a time, and only at the end of another creature's turn. Spent legendary actions are regained at the start of each turn.

Attack (Cost 1 Action). The Scarecrow can make one attack with its Scythe or use Life Drain

Down the rabbit hole (cost 2 actions). As long as the scarecrow is in a field used for growing crops, it may use its action to disengage by sinking into the ground and reappear instantly in an empty space within 30 feet

Terrifying Shriek (Cost 2 actions) .  The scarecrow targets one creature it can see within 30 feet of it. If the target can see the scarecrow, the target must succeed on a DC 17  Wisdom saving throw or be magically frightened until the end of the scarecrow’s next turn. The frightened target is paralyzed. Any creatures other than the target within 10 feet and can hear the shriek of the scarecrow must make a DC 15 wisdom saving throw or be frightened for one minute 

 Create Scarecrow (Cost 3 actions). The Scarecrow targets a pile of dead grass withing 30 feet and animates it into a scarecrow (see MMpg. 268)