Henry Wright

This WordPress plugin will generate a default avatar for each user. Each default avatar is likely to be unique.
<h3>Requirements</h3>
You will need to compile PHP with the GD library for this plugin to work.

Default Avatars

Fun default avatars for your WordPress site.

SuitePlugins

BuddyPress Private Avatar gives users an extra sense of security by allowing them to hide their profile picture from guests and members that are not friends of the user.
BP Private Avatar is perfect for all social network sites built using BuddyPress. It works great for the following types of social networks; Education, Health Community, Business, Dating and so much more.
Users simply go to the Profile Settings and choose ‘Make Profile Photo Private’ to hide the Avatar.
Looking for more BuddyPress plugins?
<a href="https://suiteplugins.com/plugins//?utm_source=wordpress&utm_medium=plugin&utm_content=bp-private-avatar" rel="nofollow ugc">SuitePlugins</a> 
<a href="https://profiles.wordpress.org/suiteplugins/" rel="nofollow ugc">SuitePlugins Repo</a>

Private Avatars for BuddyPress

BP Private Avatars allows users to hide the avatar to only friend connections for additional privacy.

Default Avatars vs Private Avatars for BuddyPress