This guide will let you know how to get the Secret ending badge and Morph in Extreme House in Infected Developer’s Piggy. You will need to follow the step-by-step instructions in this guide to get it.
To get the Badge, you first need to open the menu and click on “Extreme House” to get Teleported. After getting Teleported, you’ll need to Unlock the White Key Doors.
In this case, you can easily use this glitch to go to the other side of the door. The reason is to prevent Penny, George and Mommy Pig from coming to you. You will need to face a corner and then quickly zoom to get to the other side to do the glitch.
If you can’t glitch, don’t worry, as there are some locations to escape without doing any glitches.
After getting the white Key, you need to enter the room at the top of the building using the stairs. Once you’re here, click on this box and click on the picture to get it; you need to come near the Question Mark on the ground floor.
Now use the Picture on this Question Mark, and walk out the door to get the Badge. 
After that, you will need to go to the Morphs Section to equip the Special Morph.