The ultimate curveball in a video game is the un-killable enemy.
Just when you've got to grip with the controls and atmosphere of the game and are having a blast laying waste to everything to see, in strolls something your weapons cause nary a scratch on, and suddenly your tactics go from full frontal assault to a quick high-step outta dodge.
No matter how big or small these enemies' roles are in the game, they will always make themselves known in the worst of ways, and are likely to be your longest-lasting memory of the whole experience.
Fear not, however, for with a little thinking outside the box and some good old player ingenuity, there are ways in which some of these invulnerable evildoers can be vanquished for good...or at least long enough for you to escape.
From all the way back to the arcade era have gamers been haunted by foes that just will not die, and with that in mind, it's all the more satisfying to be able to inflict on them the fate they've doled out to us so many times before.
8. Earthshapers - Spyro 2: Gateway To Glimmer
As anyone who has played them will know, the combat in the original Spyro The Dragon games is far from complicated. Usually, whatever isn't killed from one charge attack can be dealt with just as easily with a single flame attack instead.
That's not the case with the Earthshapers of Fracture Hills, though, for getting rid of them requires a bit more ingenuity.
In part of the level, these stony giants are deliberately positioned next to lava pools, so all you need to do is charge them enough times for them to fall in. But another area features no such advantage, leaving you wondering if these particular Earthshapers are totally invincible.
This invulnerability plays annoyingly into a side quest involving escorting a frail alchemist straight through the clump of Earthshapers, but luckily, you can get your own back if you happen to come across a Supercharge panel somewhere on the floor of the level.
As long as you can get there without bumping into anything, the unaware brutes don't stand a chance, and you can now bulldoze through them like they're made of cinder toffee. For all the grief they've put you through, it's endlessly satisfying.