Underwear that's fun to wear! Underwear that's sure to earn you a beating if you wore it out in public!
Underoos were an amazingly-successful line of kids underwear from the late 70s/early 80s and had a bunch of DC and Marvel characters covered (I guess they could've just slapped a Casper logo on some tightie-whities and made a few bucks for Harvey). As you can see from the second picture, I was quite proud of my Aquamans. They didn't earn me a beating, but it was close.
A couple of months ago, I found someone selling a still-sealed package of them on ebay. After a massive bidding war, I came away victorious, having paid an absurdly-high amount for a package of kids underwear.
Sometimes being an Aquaman collector is a long, lonely road.