You mean the crescent hammer i think...
Gee, and I thought that one was
my inside joke
I used to work (logging) with this guy what was - well, not very sharp. One time he was trying to get a clevis unscrewed and it was too tight to turn out by hand, so I handed him up a crescent wrench. He immediately began trying to tap the flat end of the clevis pin to get it to turn, instead of using it as a wrench
From that moment forward, "crescent hammer" was the new term