Over or Under CRed Monsters?

[JNAProductions]

What are they? How many are there? Etc. etc.

[Jowgen]

There is no shortage of them and many a thread devoted to the topic.

But if you just want a place to start, Monster Manual II has some of the worst offenders. Start with the Adamantine Horror.

[emeraldstreak]

As a rule of thumb all true dragons and all MMIII entries are slightly under CRed.

[hamishspence]

Going by the Fiendish Codexes providing consistently lower CRs for various fiends from previous books - the idea seems to be that most MM2 and Fiend Folio fiends are over-CRd.

[Inevitability]

Allips and shadows aren't too ridiculous stat-wise, but most 3rd-level parties are not going to have a means of reliably killing them. The same goes for swarms, though those are slightly less dangerous.

Also, planetars. You can't have a monster with level 17 cleric casting and a ton of other abilities (3/day Raise Dead as a SLA, permanent True Seeing, Regeneration...) and say the resulting monster is CR 16. Same goes for Ghaele eladrin.

[gorfnab]

Even though these threads are archived, they provide quite a few badly CRed monsters.
The most unbalanced monsters for each CR up to 20 (or so)? (http://www.giantitp.com/forums/archive/index.php/t-315230.html)
Worst CR'ed Monsters (http://www.giantitp.com/forums/archive/index.php/t-450833.html)
That's ONLY CR 9??? Let's Read: The Monster Manual II
(http://www.giantitp.com/forums/archive/index.php/t-187046.html)

[hamishspence]

You can't have a monster with level 17 cleric casting and a ton of other abilities (3/day Raise Dead as a SLA, permanent True Seeing, Regeneration...) and say the resulting monster is CR 16. Same goes for Ghaele eladrin.

Yup. MM2 weirds had the same issue only vastly more so - CR12 monster, casts as 18th level cleric, has lots of powers on top of that.

Might win the prize for "biggest gap between listed CR and "true" CR. Even with Frostburn (and possibly errata?) changing it to CR15 as the default for Elemental Weirds in general, that's still a big gap.

[Arkain]

In MMI alone there's swarms and incorporeals, for starters. An allip or shadow can easily destroy a low level party. Bat swarms are invulnerable to weapon damage, so I hope you brought some alchemist's fire, Burning Hands or whatever else to deal damage in an area of effect, otherwise that might be it for you.

[flappeercraft]

That Damn Crab (http://archive.wizards.com/default.asp?x=dnd/fw/20040221a) is what you're looking for. It's CR 3, compare it to an Ogre which is also CR 3. Totally balanced right?

[martixy]

For my book, the most hilariously under-CRed monster is the adamantine horror.

CR 9.
Disintegrate, Implosion and Disjunction.
At-will.

[Esprit15]

Drowned are rather terrifying to an even slightly unprepared party. If you don’t have water breathing, no need to breathe, or an impressively high CON, you are a single bad roll away from its aura slaughtering you.