I can remember as a kid, either in the late 1970s or early 1980s, going to a museum in the DC area that had a giant stuffed porcupine. If you got close to it an “alarm” went off which was a recorded voice saying, “Uh-uh, never touch a porcupine!” My brother and sister remember this too but our parents don’t. I don’t think it was one of the major museums (Natural History etc) because I don’t remember seeing it often, but I can’t for the life of me remember where it was. Google is no help. Anyone?
Capital Children’s Museum, maybe? (I have no memory of the porcupine, but it sounds like the sort of thing they might have.)
I was going to suggest the same thing. We haven’t been in about 10 years (well, it’s gone nowadays and won’t be back for years) and I don’t recall seeing such a thing, but that’s the most logical place to find such a porcupine.
Oh - and it was a block or so away from Union Station - we used to drive to the station and park there, and walk to the museum.
My guess is the National Postal Museum.
The National Postal Museum is a block from Union Station, but it’s not very porcupine-centric.