Complex sentence: The grue is a frequent joke in Uncyclopedia and they're considered to be indestructible and they also consider that Chuck Norris is actually a grue and the best representation of a grue is Domo-kun.
Split into simpler sentences: The grue is a frequent joke in Uncyclopedia and according by them they're indestructible and that Chuck Norris is actually a grue. And also according to them, the best representation of a grue is Domo-kun.