Octopi hold all their guts in that sack above their eyes and brain, so it's a heavy part their body. The sac should be pulled down by gravity a lot more, especially out of water much like this little guy's:
Also on the octopus, the tentacle lines you have underneath his eyeballs shouldn't fold up like that because they don't extend that far into his face.
I like the yeti, but he's much more simple in shape and shading than the octopus, so the focus of the image goes straight to your cephalopod (doesn't help that the octopus has a bold outline where your yeti does not. ) I'd recommend simplifying the octopus; the bumpy texture of his gut sac should actually be smooth, so just giving him more solid coloring like the yeti could be a solution to the detailing issue.
'sides that I'm loving the octopus' tentacles and the yeti's bloody mouth. Maybe add some fangs and red eyes to make him look more fearsome?