Go to Options > Resource Packs > Open Resource Pack Folder (or the "Upload" button in the web interface). Activate: Move the pack to the "Selected" column.
Specifically looks for air pockets and underground structures. Method 3: The "Lag" and "Piston" Glitches xray hacks for eaglercraft exclusive
Search for "Minecraft 1.8.8 X-Ray Texture Pack" (Eaglercraft is based on 1.8.8). Go to Options > Resource Packs > Open
Some developers have created "Exclusive" Eaglercraft clients that come with built-in cheat menus. These are essentially modified versions of the game’s source code. Key Features of X-Ray Clients: xray hacks for eaglercraft exclusive