It isn't obvious what type of clothing this is.
When discovered, it was billed as 'pajama top' but really, how do you tell? Did it have bottoms to match? This has the somewhat unusual 'laughing Sonic' stock art, and the 'broken bricks' style Sonic name. It's on a female mannequin, but it likely wasn't 'just for girls'. This was from 1994, and is not that common.
Sleep in Sonic Style with these pajamas!
This is a set of PJs with long sleeve top and pants. (the pants are folded oddly to fit into the photo) These have various familiar stock art Sonics zooming all over in large sizes, and the "Broken Bricks" style Sonic name. There are also a few logos on them. Not a bad set if you can find it, and fit into it. What sizes did this come in?
These two photos (if put together) illustrate a complete Sonic Tie. The top has repeated patterns of just a stock art running, and the bottom has a somewhat less-cool Sonic with the 'spinny legs' on a traditional checker background. It is not known if this is a kids or adults tie, or what it is made of.
Photo credit is GreatThings4U
A multi-pose t-shirt heads things off. This is an unusual shirt with a design on both front AND back (not something you see often in the past, or current lines) The front features lots of stock-art poses, gathered around the big foreward facing head. Sonic is impatient on the large design on the back. There may also have been a sweatshirt or long-sleeve, with the same design.
This rather simple shirt was a give-away at some store, when you bought or possibly pre-ordered Sonic 2 for the Genisis/Megadrive. It is likely from the USA. Notice that it is a "Hanes" t-shirt, and does not seem to have been licensed, although there is a "Sega" logo.
The design is ordinary, but the stock-art Tails is nice looking, as it hasn't yet mutated.
Even a game as unpopular as Sonic Spinball got some shirts! These were released around the time of the game (obviously) and one has the cover art on it, complete with mountain fortress and strange eyeless Eggman.
This other Sonic Spinball shirt actually says the name of the game and features a stock art running away from a pinball bumper while Eggman invates a "pinball style" score keeping item.
Ah, at last.
SonicGear finally aquires a photo of the fabled Sonic Underwear. Why such a big deal? Because they're darn near impossible to find. After all, this isn't something you can sell after you've worn it! And it IS underwear, so it wears out with all the washing and gets thrown out.
Fortunatly, someone's saved a whole package! It's now proven to exist. As you can see, it was a part of Fruit of the Loom's "Funpants" line. As expected for the timing of the release/design, it's just a stock art, with some checkers and rings scattered around a logo. Why they chose a "Busting Through" type of design for underwear is a bit of a mystery because really, do you want anything to look like it is 'bustin' thru' your underwear? No. Because then it stabs you in the butt, which is where this design is placed.