TVS Diode Selection for Automotive
You can just use a normal diode (well not exactly normal but close) in parallel for that, however, it may be better to consider a reverse polarity protection circuit rather than trying to blow a huge fuse.
If your fuse takes a few seconds to blow at say, 50A, thats around 1V * 50A * 3 sec = 150J, which is a pretty large amount of heat. At that level, you will have to consider physical factors like proximity of diode to other components, heatsinking, etc.
This is a simple circuit, there are more complex ones, or ICs that handle it for you. Your high current means you will need a good mosfet, but thats not really a problem  (for example).
Another thing you may want to consider is load dumps. These high voltage pulses carry huge amounts of energy, and will explode most TVS devices you would reasonably use. I would do some research into your system to see if these can exist on your device, and look into ISO16750-2. Is this something you're actually going to sell? Or just a one off thing you want to make? If the latter, you might be able to get away with ignoring load dumps.