I am highly doubtful that any organism from Earth could survive on the Sun. For starters, the Sun doesn't really have a "surface", it just has a layer through which we can no longer see. This means there is no real "ground" that could support the organism from being pulled into the Sun. This is a bit like looking ahead at a dense patch of fog. You know it's not a wall, and yet you can't really see through it. Secondly, and probably more importantly, the very high temperatures at the Sun (5 thousand to 1 million degrees, depending on your height!), anything that can survive on our relatively chilly planet, would probably be incinerated long before it got to the Sun. Scientists are working on two new satellites - Solar Probe Plus, and Solar Orbiter, that will go closer to the Sun than ever before. Even with these special materials, the satellite can't go closer than thousands of kilometers away without burning up!