everyone already knows about my character flaw

Pine martens are an option!

I went pine marten, as I've been involved in helping their reintroduction to Wales, and then I wrestled with myself for an Age before finally going hedgehog.

Birds: puffins were the easiest choice. The UK - and Pembrokeshire Coast National Park in west Wales specifically - has a significant portion of the global breeding population of puffins, thanks to Skomer and Grassholm islands. In a country with the biodiversity depletion we have (bottom 10% of countries globally for biodiversity), the islands of Pembrokeshire are almost obscene in how high their biodiversity is, and it's for breeding specifically. We can be justly proud of those. Plus, puffins are fun clowns.

And then I agonised about the others until I finally went for the Great Spotted Woodpecker, a bird I do periodically see and get excited about every time

The Lumped-Together-Others: the bumblebee, you have to. I adore bumblebees.

And then I went for the marsh fritillary, because it's super endangered and I'm an environmentalist with a specialism in habitat management and ecology, and therefore spend a non-trivial amount of my time explaining how to manage for the little assholes.