A better and vanilla-compatible version of Headed.
Mainly, it changes the rendering of certain player heads to look like new blocks. Here's an example with Headed Rewritten (left) and vanilla (right):
Additionally, it adds a Creative item group with all the added heads.
If Headed Rewritten is installed on the server, players with Headed Rewritten installed will see more accurate hitboxes (if it isn't installed, the head hitboxes will have a minimum size of 8x8x8 to avoid glitches).
Also, adding Headed Rewritten to a server will make mobs killed by a charged creeper drop their heads.
Thanks to Vanilla Tweaks for the head textures for when someone doesn't have Headed Rewritten.
To add a head to the client (for rendering), call TextureToHeadMap.addHeadNotInGroup(). The first parameter is the texture whose head will be replaced (the string in Properties:{textures:[{Value:"String"}]} is JSON encoded in Base64, so you'll have to decode that in order to get the texture).
You can call HeadedHead.toStack() if you want a stack of the head. TextureToHeadMap.addHeadNotInGroup() returns a HeadedHead.
To add a head to the server (for easier creation of a stack through HeadedServerHead.stack(), HeadedServerHead.entry() and HeadedServerHead.entryBuilder()), you can call TextureToServerHeadMap.addHead().