the strangest thing I have ever dissected was an eel that was over a meter long! So all organs are quite long and the stomach and gut is like 50cms long and was full of small fish: I found over 70 in that eels stomach!
It also had a lot of fat everywhere, which was pretty unpleasant.
If you like gory stuff then follow this link, someone has done an eel dissection and wrote a blog about it:
I only studied zoology in my first year in college (most science courses start off with all subjects and then let you specialise), so I haven’t dissected anything beyond what they show you in 1st year. So I’ve dissected several plants and seaweeds, as well as an earthworm, cockroach, sea mussel and a sheep’s heart.