Harpy

	Classic	Expert	Master	Legendary (For the Worthy)
Life	100	200	300	400
Attack	25	50	75	133
Defense	8	8	8	8
Knockback Taken	60% (Med)	54% (Med)	48% (Med)	48% (Med)
Coins	3	750	750	1050

The last column is Master mode in a world made with the For the Worthy seed. Its numbers were measured in the game, not computed here.

For one player in a world before Hardmode. Expert and Master scale life, attack, knockback and coins by the game's own multipliers.

Coins: each kill rolls the coins from 80% to 175% of this value, then rarer extra rolls can add more.

In a Hardmode world

On Expert and Master, a Hardmode world raises weak enemies: when attack plus defense plus a quarter of life is under 80 (100 after Plantera), the game multiplies them up.

World	Life	Attack	Defense	Knockback Taken	Coins
Expert, In Hardmode	220	44	8	54% (Med)	6
Master, In Hardmode	330	66	8	48% (Med)	6
Legendary, In Hardmode	440	117	8	48% (Med)	840
Expert, After Plantera	220	44	8	54% (Med)	6
Master, After Plantera	330	66	8	48% (Med)	6
Legendary, After Plantera	440	117	8	48% (Med)	840

Classic

Item	Quantity	Chance	Kills for 50%	Kills for 90%	Conditions
Feather	1	1/2 (50%)	1	4
Chicken Nugget	1	1/50 (2%)	35	114	Not from enemies spawned by a statue
Giant Harpy Feather	1	1/150 (0.67%)	104	345

Expert

Item	Quantity	Chance	Kills for 50%	Kills for 90%	Conditions
Feather	1	1/2 (50%)	1	4
Chicken Nugget	1	1/50 (2%)	35	114	Not from enemies spawned by a statue
Giant Harpy Feather	1	1/150 (0.67%)	104	345

Master

Item	Quantity	Chance	Kills for 50%	Kills for 90%	Conditions
Feather	1	1/2 (50%)	1	4
Chicken Nugget	1	1/50 (2%)	35	114	Not from enemies spawned by a statue
Giant Harpy Feather	1	1/150 (0.67%)	104	345

Chance is per kill. Kills for 50% and 90% is how many kills give that chance to see the item at least once.