I'd like to see more done with advisors with synergistic political/player choice abilities.
Gargoyles with a different take on 'coming to life' could be cool. I think of the 'hidden' enchantment cycle in Urza's Saga as a starting point.
Griffins could really use some curve fillers, everything is bunched at 4-5 CMC for the most part.
I'll second cephalids & octopi [octopuses, octopodes, take your pick, according to Merriam-Webster, apparently all can be used], along with krakens and leviathans. Add in some human cult followers that do sacrificial things like Eldritch Moon was trying to do with cards like
Emrakul's Evangel and
Foul Emissary and get some more Cthulhu-ian flavor. Maybe staple oozes in here as well?