This chocolate-colored Onesie-like bodysuit by Enfant Terrible is the closest thing I've seen to an "I Hog The Ground" costume. Sure, the little flocked creature on there is supposed to be a teddy bear, but though the belly's a little too round for a Steven, with those ears, I bet you could still pass it off as a Steve.
Longsleeve Teddy Bear [sic] Onesie [sic], $28 at Enfant Terrible [shopenfantterrible.com]
Previously: "I Hog The Ground" Video By Steve & Steven: Great Ideas From, For Noggin