From the Super Mario Wiki
Retrieved from "http://www.mariowiki.com/index.php?title=Needlenose&oldid=2121566"
Needlenoses, or Needles, are a type of Pokey that certain enemies spit. They take the shape of a yellow or green spiky ball. They can be turned into eggs. Needlenoses appear in Super Mario World 2: Yoshi's Island, Yoshi's Island: Super Mario Advance 3, Yoshi Touch & Go, Yoshi's Island DS and Yoshi's New Island.
Yellow Needlenoses, when spat at a Yoshi, will pop. Green Needlenoses will bounce. They can be spat from Priscilla, a Blow Hard and its relatives, or a Wild Ptooie Piranha. A Needlenose will also sometimes bounce on top of a Pokey. If Yoshi defeats or eats the Needlenose, the Pokey will frown and lay down. However, it will reproduce another Needlenose shortly after. Also, they can be spit out by some Egg-Plants if Yoshi has less than six eggs with him.