The salak fruit, native to Indonesia, has an outer skin resembling that of a snake. The pulp inside divides into three edible lobes. Agriculture Guide has pictures of this fruit and fourteen other odd-looking fruits and vegetables.
Link via The Presurfer | Photo by Flickr user Jayson Emery used under Creative Commons license
The spikes of durian are _hard_. You could make a mace with it, though I haven't ever heard that it's ever been done! It's stinky and it's not worth trying, if you ask me.
In the US, lychee can be found in a can at any Asian mart. Buy some. No adventurousness necessary. It's fragrant and sweet. It has great potential for fancy dessert recipes. Mostly, it's eaten plain.
salak tastes very good (sweet) if you pick the correct ones.