Emoji taken and organized from r/mylittlepony's emote_guide
Special Thanks to @SteveStreza for pointing out /r/mylittlepony/.
Open your Org's customize pane and upload them by hand:
https://<org>.slack.com/customize/emoji
Optionally there is a bulk uploader based in npm named emojipacks.
Emojipacks software relies on a newer version of nodejs than Ubuntu14 Ships. I recommend installing it into a Container (Docker) or VM (Virtualbox), and patching that environment as documented in this comment
Emojipacks relies on plaintext credentials!! so I recommend also using a non-admin slack account, and change its password or delete the account after uploading.