Maybe allow a new save as a full round action each round? That way, the players have at least 1 die roll to do each round, and they have a chance of getting back in the action, which is fun.
Nothing is worse than being paralyzed, dazed, asleep, or stunned for an entire fight. Even if you die, at least you can begin rolling up a new character. Even running away with a feat effect lets you (somewhat) decide the path away from your peril. Just standing there or lying around doing nothing.
I actually had to rewind an encounter with a few Necrophidus for a brand new group. The only one capable of overcoming their DR kept failing his save against the dance, the rest either had the wrong kind of weapons or couldn't deal enough to matter. So I reset the encounter, redid a few characters and then went at it much easier.
Oh gods. 30 foot round room + Necrophidius + only one party member with a bludgeoning weapon = 29 rounds of combat.
The only thing that kept us from having any deaths were the five(!) divine casters in the party.
Ah... we played **Spoiler**, when we got to that room with 6 first level characters it was a near TPK, another group playing the same night lost one character and nearly the whole party. At a later time I was GMing that and TPKed a 4 player party.
Good grief, this thing is terrifying! I ran an encounter for an APL 3ish party. It's CR 3. That should mean a fairly straightforward speedbump in their adventuring day, right?
DC 15 will save or be dazed for 2d4 rounds, to everyone within 30 feet.
DC 13 fort save on bite or be paralysed for 1d4 rounds.
This thing is a low-level TPK machine.
Does it need a fix?
The saves could probably push it to a CR 4, but I don't see it as a TPK for a 3rd level party unless there are a lot of bad saves, but bad rolls can kill anyone so I can't really go off of that. It still only has an AC of 15, and switching to a bludgeoning weapon bypass the DR.
Edit:My group are normally pretty optimized though. I think it also depends on where the encounter takes place.