In Paper Mario: The Thousand-Year Door's root file structure, the game's audience and battle HUD sprites is stored in root/battle with three subfolders.
The tpl format is a compressed file format that contains .tga files, which can be opened by most graphical editing programs.
Stores the graphics for Mario's action selection menu, such as the hammer, jump, item, tactics, and swap partner icons.
Luigi's audience graphics.
Normal enemy audience graphics.
Toad audience graphics.
Battle HUD graphics are in this file.
Misc or extra battle HUD graphics are in this file.