Why does my Duncan look like this?

[Oaks]

What could this be? Also kinda looks like a brown ball thing in his mouth?

 

[brandon429]

sometimes lps expel gut materials and zoox at other times and they can look strange like that for a while. duncans behavior is bizarre anyway, I wouldn't judge health or tank happiness off a Duncan Id go from the other corals and it w eventually behave if they do