Brad loves to tote Arnie. You know, just walk around with an Arnie draped about his shoulders like a cape. It's REALLY normal behavior. Most people walk around with dogs (who weigh HALF AS MUCH as they do) around their necks.
Arnie's so mellow, though, that he never really minds, especially when he's really stoned, as he is below:
Arnie isn't as into it when Brad tries to get him all fired up. Arnie doesn't do "fired up," which is unfortunate, because Brad doesn't do mellow. Yet, like Bert and Ernie, they get along famously. As you can see.
Oh, and the wetness on Arnie's head, that's making his fur all cowlicky? That's where Brad was biting him.