For old school, how about the Cyberdemon in Doom?
My confusion with the chosen items was the point of my post. The creator of the list is irrelevant. 
I can’t believe Doom is old school. I feel so old.
Definitely Bald Bull from Punch Out. Up till that point, enemies had patterns and timing was involved, but it was fairly forgiving. But during the Bull Charge you had to hit him at JUST the right moment.
Dodge, and he simply winds up for another- its a game of chicken. Mis time your own punch, and you’re on the canvas yourself. Its very frustrating at first, but VERY SATISFYING to see that smug jackasses shocked grimace as he keels over in defeat 
Well, I couldn’t remember the names of the bosses in Wing Commander 1.
Since I haven’t played any Pokemon game, I can’t tell whether their N°1 is accurate, but Matador is an asshole allright. A cheap asshole at that, since he comes right out of left field unannounced, with a power level leagues above any boss you have encountered so far (and above quite a few bosses you’ll meet after him, too…) and the monsters you can recruit in the dungeon prior to meeting him are almost all weak to the attacks he dishes out, which makes him exponentially more efficient at raping you, even if you’ve only got the one on your team. Fuck Matador with a rusty nine iron, seriously.
Those are not wake up bosses. A wake up boss is an very hard enemy that springs up as you’re getting into your groove in a game, beat up big guys, figure it’s easy and start thinking you’re the shit… then they stomp you. Repeatedly.
By comparison, you fully expect a raid boss to be hard, and you come in loaded for bear.
This. Wake up call bosses have to show up very early in the game, and they’re generally not that hard once you’ve figured out how the game wants you to play. What most people are describing is that one boss.
I have to mention Mr. Gold and Mr. Silver from God Hand, who really fit the definition to a T: once you’ve figured out how to play, they’re not that hard, but until that point they will kick your ass every single time.
The Metal Gear Solid games pretty much all have the first boss a wake up boss. Mainly because the strategy for taking out bosses is almost always different from taking out mooks.
I agree and I messed up by putting the Dragon God from Chrono Cross. It’s just that even late in the game, I was having an easy-average time with it and he woke me up out of my trance for sure.
Persona 3 and 4, though, have some early bosses that just smother you whether you are prepared or not.
Was that the Rocketlauncher-for-arms-dude? Once I learned to dodge the missiles it was easy. That damn spider was meaner, with its hitscan-bullets…