Please note: all credit goes to Spacey!
A guide on how to beat the Big Mouser boss from the first TMNT on NES risk-free.
Guide to Defeat Big Mouser (NES)
The only thing that is required before entering the boss is either Donatello or Leonardo since they can attack farther away making this strategy less risky and makes it possible to do the boss without taking damage (Donatello is more recommended since he can attack the boss on the ground because of his slightly longer weapon).
- Choose Donatello or Leonardo (Like mentioned in the prerequisite section).
- Stand in the middle of the Giant Mouser (Like just like the image below).
- When the Giant Mouser opens it’s mouth (see image below) pause the game (In-game pause not the collection pause).
- If done successfully the core should be exposed despite the mouth being closed and then you should attack it fast!
- If the Big Mouser decides to open it’s mouth again repeat steps 3 & 4 until the boss is defeated.
Congratulations you have now successfully beaten Big Mouser without any effort!