This mod adds "carved" variants of most "terracotta" blocks in 1.12.2
To obtain them, you will need to craft a Block Carver;
Block Carver recipe:
C= crafting table; c= copper ingot; i = iron ingot; s = cobblestone;
0 0 0
s C s
c i c
Once this block has been placed, simply insert the terracotta block you wish to carve into its inventory, and click the button.