Sometimes, I generate RSA and ECDSA keys for the randomart. We’ve also had a vulture and a camel.

+--[ RSA 4096]----+
|                 |
|                 |
|                 |
|     o . ..      |
|      = S+ o     |
|     . =E.+      |
|      +o+o       |
|       BB  .     |
|      +=ooo      |
+-----------------+
Github Gist