I love when you add a detail to a piece of art and it just nails some salient feature. For the cow, I looked at some pictures and decided that was a thick rectangle body and a little knob on its head.
Now, if someone said to draw an arrow, I'd probably draw something that looked like the picture on the right there. The requisite features: a triangular tip and a good length of feathers on the end, (of which there are always appear to be two, though I'll chalk that up to perspective).
I'm always amazed when I look at my actual arrows. They taper to a little point. They have three plastic vanes instead of feathers which are much smaller than one might expect. If there were feathers, they'd be smaller in proportion to the shaft than what you see in most illustrations. I've often wondered if anyone who hasn't done archery would recognize what they are.
I'm really sorry I didn't ask to keep the cow when the show was done. It was stellar.