Stonehewer Giant's ability doesn't target a creature. However, the creature must be able to be legally equipped by the Equipment. For example, you could attach the Equipment to a creature with shroud, but not to one with protection from artifacts.
07-08-2020
wotc
If there is no legal creature for you to attach the Equipment to, it remains on the battlefield unattached.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.