All about the same shape and size- I suspect they are all Humboldt penguins. The members of PPP come from species of wildly different sizes. So yeah, it doesn't belong in the pool.
I think it belongs in the pool, I mean, the pool description states:
Any pictures depicting any animal character as (or with) their respective animal form.
I'd like to think it also means the character must be with an animal of the species they represent even if it's not them specifically... I may be wrong tho...