You need a Huggable character that knows "So Fly" to do this. On the huggable factory map, go to the right of the red base, where the platform meets the wall. Look up at where the boxes are. Use "So Fly" and fly up. Make sure no one sees you, as you can still be shot. Move a bit farther back, but not too far, as you will die. There you go! Now to can use a healing tent without the risk of someone shooting you, or when someone passes by beneath you, jump down and melee them to death, then fly back up!
Super Huggable Invincibilitly Code
This is ONLY for the Pyramid map! (Newest map). First, you have to have "Mini Me" for Secondary and "Headlights" for Primary using the Huggable. Second, go the enemy pyramid and start climbing up. Go to the upper right hand corner and fall down only 2 TIMES!!! Then go towards the center and mini me in the corner. The you will be in the staircase that is on top of the pyramid. Wait to grow back to normal size while still in the staircase. The staircase acts as it's not there , so use headlights and it will go right throught the staircase.
Tillman hint
Have explosives+1 or 2 in both equipment slots and be careful not to die use turkish sw boots ok my work is done and also happy killing.