The "hump"in the grip matches the cane.
Are you familiar with a "bang stick"?
This is a 3 to 4 foot long stick or metal rod with a 1 shot screw together cartridge holder that is used on sharks or other big fish brought alongside of a sports fishing boat.
You un-screw the barrel/chamber, insert the cartridge, screw it back together.
When you jab something, the cartridge fires.
They are made with pistol or rifle or shotgun ammo.
I had one here I kept when I sold my offshore boat in 2006.
Mine is 223 cal.(5.56).
I have mounted the firing device on the end of my walking stick.
A walking bang stick.
You can see the green tip of the 55 gr projectile if you look.
Again, to fire it, you have to jam it against the object forcefully.