A spiky rambutan ? A hybrid plant between rambutan (Rambutan means hairy fruit in Malay) and lychee?
Pulasan is a tropical fruit that looks like a rambutan. To me is a wild rambutan (which is not true) because of its look. It tastes much sweeter than the normal rambutan. It also has a thicker shell/skin... spiky but not hairy. Very interesting looking fruit.
The name pulasan comes from the Malay word pulas (twist). The fruit is opened through the act of twisting the fruit with both hands, thus the name pulasan.