I remember a pair of Luftwaffe F4s using the c/s "Hitman 1&2" a few years ago - that was pretty cool, especially as the leader had quite a deep, gruff voice! I think they were from Wittmundhafen.
I also remember another time when a colleague had a call from a pair of USAF A10s c/s Gunhog. For some reason he thought they were called Kellogg, like the british cereal. The A10 mate kept saying "Sir the callsign is Gunhog," to which my oppo replied ", Kellog roger." After the third attempt to explain it the Yank gave up, left the CTR and went en-route VFR. The rest of us were in stitches. To this day, my colleague still maintains that they were c/s Kellogg!