No blue whales? (Up to 108 feet long and 150 tons) http://www.acsonline.org/factpack/bluewhl.htmI do like the sea critter idea:
0-50 posts: virus
50-100 posts: bacterium
100-250 posts: amoeba
250-500 posts: plankton
500-1000 posts: krill
750-1000 posts: fish
1500-2000 posts: shark
2000-3000 posts: orca
3000-4000 posts: beluga
4000-5000 posts: humpback
5000-10,000 posts: kraken
Let's see if we can come up with anything else and then we'll run a poll.
or playful octopi?