[rimiform]

You can create icebergs with 'holes' in them, which have very interesting floating behaviour [0]. It doesn't work every time, though. Not sure why.

[0] https://imgur.com/a/0lcW8xT

[Enginerrrd]

This works for the classic ice-cream cone shape to induce stable dynamics too.

[0]https://imgur.com/a/F5TshLR