A scientist got the surprise of his life when he stumbled across a puppy-sized spider.Piotr Naskrecki, an entomologist, said the sound of the Goliath birdeater walking resembled the clip-clopping of horse hooves.He spotted the beast on a trek in the Amazonian rainforest. read more Puppy-sized spider found in Amazonian rainforest and it sounds like a…