That is a good question. There are two types of perception when it comes to names: personal perception and mass perception. Personal perception is when you identify the name with something in your own life (a schoolyard bully, past boyfriend). Mass perception is when you–and others–would associate the name with a famous person, character or celebrity (Adolf, Oprah, or Scarlett).
When it comes to Barny, yes, I would think of either the purple dinosaur or the character on How I Met Your Mother. Or Barney Fife from the Andy Griffith show (although that dates me). None of the three are very great associations.
Look at the name from the perspective of the child. Can it grow with him? Will it be an advantage or a burden? Think about this and then decide.