Anglerfish animated! I had some trouble with him following the path (at first he just went all over the place, I had better luck animating the path before the swim cycle, but he still wasn't quite on the path and tended to zoom around corners. This all is why the path is pretty simple). 

A couple of other things that didn't seem to work right was copying and pasting weights (I think that was something early on, I ended up having to do the right and left side seperately) and for me alt D made new versions of strips (same as shift D, not instances as it did for you). I also noticed that adding depth of field made the entire render come out black...so I didn't use that in the end. 

Despite the occassional difficulties I really enjoyed this course, it was great to do so many different (often challenging things). I definitely feel inspired to try out animation again. I especially am grateful you include the NLA as that to me opens up a lot of possibility when you are not trying to animate everything on one strip, and also the graph editor (its doesn't feel like so much of a confusing mess now!)

Any feedback is appreciated, thank you.