I would say either a free verse poem or a short story.
Free verse- You are not constrained to a meter and it doesn't have to rhyme. You can get your point across without limiting your thoughts!
Short Story- Your example can be taught in a fictional genre, a non-fictional genre and it can be as long as you want it to be!
Hope this helps!
The main idea of the paragraph would be the penguins camouflage and feathers help them in their survival
3 supporting facts would be: it makes them hard to see in the ocean for predators, they blend with they sky, their feathers protects them while swimming and keeps them warm.
(this could be worded better but yeah, hope I could help!)
Got any more details id be happy to help
A. Suddenly B. Very C. Softly