I'm glad to see that other folks had the same reaction as me - namely, "oh no, how mean." I had pet rats for years, so I know they can swim well and they'll be fine, but still, the poor things must be terrified. :(
If you cover up the jaws with your thumb while you look at the picture, it's obvious that it's just a sealion body on its back, that he's reamed out and sliced up the front and inserted tiger jaws into.
Translation: 14th January, 1965 With this (offering) I give my most sincere thanks to the Virgin of Guadalupe who gave me the miracle of recuperating my power of speech when I was left without being able to speak when I saw a ship with a strange being coming out of it. 20th Abril 1984.
Thumbscrew! I saw one of these in the San Francisco Wax Museum of Torture (or something like that). The guy I was with had to leave halfway through. :)
Looks to me like one of the tools used for preparing animal hides: after you scrape the subcutaneous layers off, the leather has to be pummeled, stretched, polished, and rubbed to make it pliable. I'd say that would be the best bet, but I'm puzzled by what looks like a piece of bone attached to the left-hand side.
Taxidermo-licious!