Particularly Angry:  This particular goose is fueled by nothing but spite for mortal kind. If it can attack, it will. Nothing and no one can persuade it to cease it's rampant rage and thirst for violence. 

Particularly Famished: Even the most evil must eat, and tireless hours of maddening conquest have left this goose starving. If there is any bread, peas or corn within 20 ft. of this creature, it rolls a WIS saving throw. On fail, it ignores all other targets and is forced to move towards said food and consume it for a turn. 

Peck. Melee Attack: +2 to hit, reach 5ft., 1 target. Hit: 1d4 + 1 Piercing damage.

Ram.  Melee Attack: +2 to hit, range 5ft., 1 target. Hit: 1d4 + 1 Bludgeoning damage. Knocks target back 5ft. 

Furious Bird Noises. Ranged Attack +2 to hit, range 5ft./30ft., 1 target. Hit: 1d6 + 2 Thunder damage. Gives target -1 to attack for the next turn. 

Instigate: As a bonus action, the Particularly Angry Goose can taunt a creature. On that creature's turn it is forced to use it's movement speed to approach, then attack the goose. 

Frighten: As a bonus action the Particularly Angry Goose can target a creature: That creature must make a DC 17 WIS saving throw. On a failed saved the creature gains the Frightened status. 

No Running From Feathery Doom:  As an attack of opportunity the Particularly Angry Goose can fly on the opposing creature's head as they flee and use a free Peck. with advantage. At the end of the opposing creature's movement the Particularly Angry Goose dismounts to an adjacent free space. 

This Legendary Action can only be used once per encounter when the Particularly Angry Goose reaches half HP or below.

Summon The Horde (Costs 1 Action). Let out an impossibly loud screech, and summon 1d2 Swarm(s) consisting of 1d20 Geese to your aid.