This resource pack was made for Ice and fire. It is much inspired by an other crazy resource pack which is Better Ender Dragon and it might not work without it, also optifine required. Now every ender dragon head will be like dragon skulls of ice and fire. It seems to be the same as a tier 2 dragon skull. Enjoy !
Here is the link of Better Ender Dragon resource pack:
https://www.curseforge.com/minecraft/texture-packs/better-ender-dragon