What is a Plz account?
Plz accounts are dA accounts created for the use of their avatar. The emote or image is placed as icon, which can then be produced in comments wherever avatars can normally be used. They are called plz accounts due to the fact most accounts end in the 3 letters plz, both to avoid using decent names and to identify their purpose.
Is there a list of Plz accounts?
There isn't an 'official' list of plz accounts, however there are a number of accounts on deviantART designed to help deviants find new plz accounts to use. Below is a list of some of these accounts:
HelpPlz
PlzShare (https://www.deviantart.com/plzshare)
plz-addict (https://www.deviantart.com/plz-addict)
Moar-PLZ-Accounts (https://www.deviantart.com/moar-plz-accounts)