UNLOCK'd ~ Mortal Kombat Reptile HD
This is how to discover Reptile in Mortal Kombat. Here I did it on SNES, with the default game settings. The requirements to fight him are the same across all platforms. Those requirement are: The stage must be the pit. You need to win both rounds via flawless victory and do a fatality (I find on SNES you can just uppercut most opponents). You cannot block. Good luck fighting Reptile! I find a combination of chest punches and foot sweeps is effective against him. Along with some well timed blocking.