Entity Explorer mod allows you to see entities through walls. Press I key to open the gui. To find out id of entity you want to find press K key and right click entity.
How to install:
- Download and install Minecraft Forge.
- Download the mod.
- Go to %appdata%.
- Go to .minecraft/mods folder.
- If the “mods” folder does not exist you can create one.
- Drag and drop the downloaded jar (zip) file into that.
- Enjoy the mod.