The Eye of Cthulhu

Not to be confused with the boss.

The Eye of Cthulhu is a Yoyo that is dropped by Mothron after Plantera has been defeated. Its best Modifier is Godly. This Yo-yo has either an extremely long "air time" or can stay out permanently, unlike the yo-yo's before it, which must be thrown again after doing either a certain amount of damage or staying out for a certain time.