As much as video games tend to reward players who venture off the beaten path and explore every nook and cranny of the game world, sometimes that "reward" isn't quite what players expect.
Sometimes that reward is simply being bodied by a hugely powerful secret boss you weren't remotely ready for.
Optional and hidden bosses are generally included in games as added challenges for more adventurous and committed players, requiring an all-compassing mastery of a game's combat systems above all else.
But some games take this to frankly ridiculous extremes with their ludicrously powerful optional bosses which can literally cleave players into a bloody mist in mere seconds.
No matter the difficulty of the base game, these 10 secret bosses upped the ante big time, forcing players to take a step back, re-evaluate the situation, possibly level up a little, and then come back swinging.
Even then, these boss fights could take hours, days, even weeks to finally beat, at which point players surely had to ponder whether all that time and energy invested was truly worth it.
For some, at least, the answer was thankfully in the affirmative...
10. Morgan Freeman - South Park: The Fractured But Whole
Morgan Freeman may be a totally optional boss in South Park: The Fractured But Whole, but you'll need to take him on if you want to pick up the "Farts over Freckles" achievement, and he presents by far the biggest challenge in the entire game.
If your Might isn't at least 750, there's really no point even trying to conquer the Oscar-winning Oscar because he'll make short work of you with little effort, using both his powerful Million Dollar Bitchslap and Fart Sensei attack.
He's also got 9999 HP, and even if you manage to whittle away half of that health, he'll then gain the opportunity to attack twice per turn and start charming members of your party.
Unless you're willing to drop the combat difficulty down to Casual, this is absolutely hellish, as Freeman can easily take out your entire party in just a few moves. Not fun.