I think that for LTTP style, 4 frames would be perfect. 2 frames for each of the 2 positions you've drawn. The extra 2 frames essentially the same but with the tentacles moved a bit to make their "waving" look smooth. That could animate really well when the dude's spinning fast.
Hell, you do that and I might even program some movement & animation in GM.
ONLY slight problem is the top "attachments" don't extend very far so it might require some kind of cover-up sprite that connects them to the invisible ceiling.