In Resident Evil Zero, the Stinger has a health value of 500, in comparison to Billy and Rebecca's 250 and 150, respectively. The boss fight with the Stinger is triggered when the player returns to the Ecliptic Express' saloon car after picking up the Ice Pick.
The Stinger will try to approach the player and either attack with its tail when it is close or ram into the player from a short distance. While moving to get into attack position, it will put up its armored claws in which it protected from being damaged. Once ready to attack, the player has a chance to damage its exposed face. It will either flinch and move back from taking enough damage, or it won't at all and will follow through with an attack meaning the player must move away to avoid being hit.
The most obvious weapon to dispatch this boss with is the Hunting Gun, which can be found in First Class private room A, through a door in the same hall where the Ice Pick is found. Aim downward when Stinger is at point blank range—the first shot should crack through the shell, and the second one should kill it. If any shotgun shells are in your inventory, you can use a second set if Stinger didn't die, or fall back on the handgun.
This boss can, with proper timing, patience, enough healing items and luck, be reliably taken on with a Combat Knife, on account of how easily the boss can be staggered. The biggest danger on most modes is the "Body Blow" attack, or if you're backed up against the door. This strategy is best done with Billy on account of his higher durability.
The Stinger is fought as the boss at the end of Train Derailment 1. It will first hold its claws up to protect itself, then lower it and prepare to attack. During this period, the player has a chance to shoot and damage it. Either the player must do enough damage to it to push it back or it will attack and harm the player, or it will follow through with a scripted attack the player has a chance to quick time event dodge.