It's actually called a skibob, and this one is for sale.
Car companies have always been about more than just cars. The likes of BMW have been associated with motorcycles and airplanes and Aston Martin is now involved with real estate, but there have been even greater divergences of purpose in recent years as many motor manufacturers market merchandise that includes everything from carbon fiber guitars to razor blades. But in the old days, merchandise was less common, and when it was made, it wasn't always for activities that one would consider timeless. A case in point is the Arova-Porsche 212 Skibob you see below, and it's certainly one of the stranger items we've seen branded by an automaker.
Porsche is no stranger to the world of winter sports, and in 1970, the German marque teamed up with Arova to manufacture only a couple hundred Arova-Porsche 212 Skibobs, commonly referred to these days as ski bikes.
Interestingly, they were designed to be easy and compact enough to fold into the front trunk of the Porsche 911 of the time, thereby making the rear-engine sportscar a relatively practical ski slope companion. The bike itself also features a storage compartment for refreshments or other items that you may wish to take with you onto the Alpine powder. All in all, it weighs just 30 pounds, but even so, top athletes (there is still an annual world championship for this sport) can achieve speeds exceeding 120 mph.
Unfortunately, the example you see in the above tweet appears to be incomplete, as the original set came with a pair of adjustable foot skis for stabilization. Even so, it should be worth a pretty penny. RM Sotheby's auctioned one in 2019 and got $4,500 for it, but another sold for $8,400 in 2020. If you think that's scandalous for a heavy ski bike that you would never use, just go browsing on eBay, where one example is listed for $14,900. That said, the above example is in less-than-perfect condition, so we imagine that you'd be able to get this for around $4,000, assuming you want an obscure conversation starter.