Innate Spellcasting. The Nameless Goose's spellcasting ability is Charisma (spell save DC 15). The Nameless Goose can innately cast the following spells, requiring no material or somatic components:
At will: arcane lock, shatter, fear, thunderous smite, wrathful smite 
1/day each: divine word, etherealness, power word stun

Evasive. When the goose is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage it succeeds on the saving throw, and only half damage if it fails.

Nimble Escape. The goose can take the Disengage or Hide action as a bonus action on each of its turns.

Multiattack. The goose uses its Honk, then makes three attacks with its Beak.

Beak. Melee Weapon Attack: +5 to hit, reach 5 ft., 1 target. Hit: 4 (1d4 + 2) piercing damage plus 10 (3d6) psychic damage. 

Honk. All creatures of the goose's choice within 120 ft. that can hear it must make a DC 15 Wisdom saving throw. On a fail, the creature is enraged, having disadvantage on attacks against any target other than the goose until the end of the goose's next turn.