What monsters were cooler in the older editions?

[Flashkannon]

Though I only have feel to base this on, I think the trap monsters and dungeon ecology monsters were more entertaining/engaging in the AD&D era. Things like:

• Trapper
• Shrieker
• Piercer
• Cloaker
• Roper
• Otyugh and Neo-Otyugh
• Gelatinous Cubes
• Slimes and Puddings

It's worth noting, while I can't say precisely how they stack up to older edition versions, all of these monsters exist in 5th edition, with the vast majority having been introduced in the Monster Manual. That said, Mimics lose their cachet real fast in 5th edition - they just don't have any staying power a few levels in, which is sad. The Hoard Mimic helps fill that gap, but it's cold comfort.

I was thinking more in terms of how it felt to be poisoned as a player. Ability damage wasn't character ending like it was in older editions but it was still enough to give you pause. you might not use anything besides con or unconsciousness poisons as a player, but fighting a giant spider was a threat to your day when it's "Guys, I don't feel so good" and a minute later you can barely lift your weapons. Again, reflective of poisons and venoms in the real world. Unlike earlier and later editions where it was "instantly liquify your organs" or "Ouch, okay put a bandaid on it, I'm good". It was tense and threatening at low levels but something still worth preparing against at high levels without being immediately life ending.

I actually like, to a degree, 5th edition poisons - the Poisoned effect, anyways. It's debilitating, and depending on the effect it can stay with you a long time. Some creatures just deal extra poison damage, which is alright, but the condition rider feels necessary.

Personally, I thought Mindflayers were much more threatening in prior editions - having fought a few in 3.5 (and almost dying) and a few in 5e (beating them into the ground like a caster who strayed too close to the front lines) it feels as though their teeth have been blunted, somewhat.