Add `ducky_skull`

[decorator-factory]

A ducky with a skull :skull:

A small shade is added to the body to increase the contrast of the skull teeth. (otherwise you can't see them at all, especially in the small version)

[kosayoda]

Thoughts on something like this instead? Front facing to keep the same :skull: style to avoid weird perspective issues, looks like its turning its head

I redid the skull to avoid licensing issues

[decorator-factory]

Front facing to keep the same skull style

But all the other duckies are facing left. Not sure how to make it work with the skull

I redid the skull to avoid licensing issues

I though twemoji were under a creative commons license https://github.com/twitter/twemoji/blob/master/LICENSE-GRAPHICS

[gustavwilliam]

@kosayoda that looks pretty nice imo.

Also, we should be fine using Twemojis (like in a lot of our other assets). I'm under the impression that the way we're using it here is allowed, especially since we give credits in this repo.

[kosayoda]

But all the other duckies are facing left. Not sure how to make it work with the skull

I think facing it left makes it thematically different from :skull: (I'm assuming that's the reason for ducky_skull), also ducky_sphere isn't strictly left facing either

I though twemoji were under a creative commons license... Also, we should be fine using Twemojis (like in a lot of our other assets)....

whoops, wasn't sure what license applied off the top of my head

I'm fine with either version, so it's up to @decorator-factory, I can add a commit with my version or merge this one as is

[decorator-factory]

But all the other duckies are facing left

Actually ducky_sphere is an exception