Betsy is a Killstreak Weapon. It requires 4 kills to activate. When Betsy is activated, the Mercenary's weapon turns into a cannon with a chinese dragon head that fires golden rays which explode on impact. Betsy has 20 ammo and no reloads. The killstreak also doesn't have a time limit, it expires after it's out of ammo.
The cannon is fully automatic, although it has poor rate of fire. It has medium range and average damage. It is mostly less useful than Mercenary's primary. However, it can be used to save ammunition.
Due to exploding bullets, you can damage yourself with Betsy, like with any other explosive weapon, but you can't damage your squadmates.
The Betsy's projectiles are instant, just like that of the Bennett's Doom.
Be careful. If you activate this killstreak while reloading, you won't be able to fire them and you will have to wait until you get killed to get back to your weapon again. Same happens with Deadly Shurikens.
- Before version 19, there was a bug. Soldiers who activated the cannon while reloading couldn't fire it. This was fixed, but only for player controlled heroes. Squadmates and enemies still have this bug.
- Betsy's appearance is a reference to the Huo-Long Heater from Team Fortress 2, an unlockable primary for the Heavy that allows him to set nearby opponents on fire.