Ravel Mod/Sea Serpent's Scales

Sea Serpent's Scales is Pre-Hardmode accessory dropped by Sea Serpent with a 75% chance. If equipped, player will get some health after being hit. This effect only works if damage dealt to the player is lower than 40. This item also gives you +2 defense.

It's especially good accessory for first fights, but it isn't that useful in later stage of the game.