Hmmm, I lean toward not, but maybe it would be nice to make the bard a little more useful. What's your opinion?
You know what, I'm going to change my mind. Let's make quakedancing Su. Maybe we can make it sound more magical in the flavor text.
Tactics:
Quakedancers approach their prey cautiously, using their innocuous appearance to get within quakedancing range. Then they dance until many victims are stunned, swallowing as many as possible before they awake.
Combat: When hungry (which is often), the quakebeast pretends to be a normal sauropod, vacuously grazing on the greenery until a good number of unsuspecting creatures are within range doing the same thing, attracted by the illusion of safety the quakedancer provides.
I think that implies it's supposed to seem innocuous, even reassuring, since it looks like an herbivore.
We can change the wording a bit, but the duration is just as long (on average) as the wait period for the two older ages of quakedancer. How about this?
Quakedancers approach their prey cautiously, using their innocuous appearance to get within quakedancing range. Then they dance, stunning their prey and swallowing as many as possible before they recover.
I dunno, I could see PCs saying, "Six legs are weird, but it looks herbivorous to me." But anyway, how's this?
Quakedancers approach their prey cautiously, hoping that animals (or foolish characters) mistake them for relatively innocuous herbivorous sauropods. Then they dance, stunning their prey and swallowing as many as possible before they recover.