As an action [This Monster] consumes the corpse of a Humanoid, monstrosity, or a beast. The Humanoid, monstrosity, or beast must have died within the last 24 hours. The target must be at least one size larger, This creature then gains 2d4 +2 hp (additional d4 per incremental size beyond two sizes larger) [This Monster] then grows into the consumed creature's size.

This can only be done once per 24 hours. This effect last 10 Minutes.

Magically consuming a Huge, or Garganteoun creature requires a DC 20 Con Save, on success [This Monster] movement becomes 5 feet, and the associated size change last 5 turns. On Failure [This Monster] gains no healing benefits and is stunned until the end of their next turn, upchucking the corpse during their stunned turn.

As an action and bonus action [This Monster] can digest the creature inside its stomach reverting to its original tiny form. 

"Their stomach is a bottomless pit that can consume any creature it deems to be a predator, no one knows where it truly goes "

Upon reaching 5th level, [This Monster] gains street cred and gains their first Tattoo, granting proficiency in the intimidation skill. The tattoo traditionally represents the personality of [This Monster], but it can also depict a wild beast or the first creature consumed with Apex Predator. The location of the tattoo can be chosen, but it is often on the wings or torso. Upon reaching level 8 and consuming Sixty-Nine creatures with Apex Predator, the tattoo radiates a magical glow, and the tattoo covers a greater amount of the duck. With this "full sleeve" tattoo, they gain improved street cred. "Have you seen Cornbread? He ate a T-Rex!" When interacting with members of criminal organizations that respect Irezumi, [This Monster] has advantage on persuasion, intimidation and deception checks. 

As a reaction, when a creature you can see within 30ft of you misses an attack, you can Viciously Honk at them causing emotional damage. The target has to succeed Con save DC (8+Con Mod + ProfBonus). On failed save, the creature has disadvantage on their next attack roll until the end of your next turn. On success, there is no effect. This ability can be used a number of times equal to your proficiency bonus. "Words may not hurt you, but honks will"

When using firearms [This Monster] has disadvantage on attack rolls due to having a natural tendency to hold firearms sideways."I may not be able to shoot, but I sure do look cool"

[ This Monster] has tiny wings that viciously flap in order to slow down [ This Monster] fall speed, allowing [ This Monster] as a reaction to cast Feather fall on [ This Monster].  "Gotta stay flyyyyy, till I die!!"

Your Constitution score increases by 2, Strength or Dex +1

Ducks/Geese mature quickly. They would be expected to settle into adulthood by age 5. They can live 10 to almost  30 years based on consumption.

Ducks are between 1 and 2 feet tall and average about 5 pounds. Your size is Tiny.

Your base waddling speed is 20 feet. Your base Swimming speed is 10 feet due to your hatred of water.

A creature has disadvantage on an attack roll against a duck if there are two or more Duck Lineage /Geeze Lineage allies within 5 feet of the creature and the ally isn't incapacitated. "These honks will be the last thing you hear"

You can speak, read, and write Common, Aarakockra. When communicating using Aarakocra, quacking is a preferred method.