Cuttlefish
I love cuttlefish, they're very fascinating creatures! What I would want to make a simple "marine fun fact" type of webpage. Something you'd see at an aquarium. Could be pages/sections based on where they are in the world, their impact on the ecosystem, etc. Would want to use lots of infographics.
More animal pages (about, zoo style, etc)
Similar to the cuttlefish idea, I could do a webpage on different animals focusing on infographics and more.
Plantcare
Focusing on a single type of plant, you'll go through the steps on how to take care, water, repot, and upkeep a certain species of plant.