The black-headed, black-chested, black-backed Steller's Jays here strike me as maybe even a bit more aggressive and outlandish than the East's Blue Jays. You can see one at www.montereybay.com/creagrus/CAlistSTJA.html.
When I'm sitting on a log, one may land on the ground ten feet away, call a few times with his hoarse "wahhh," snap up an acorn and fly away.
There's a small boat here filled with water. Jays and other species enter the boat to drink and bathe. If the boat becomes too crowded, the jay suddenly screams its alarm call, flashes its wings and, while the other birds frantically escape into the trees, the jay simply hops onto the boat's side, looks around nonchalantly, and quickly hops back into the boat and continues his ablutions alone.
In a similar vein, it does a fantastic job imitating the call of a soaring hawk. Of course this call unnerves other perching birds nearly as much as the jay's alarm calls, yet it's nothing to see a Steller's Jay calmly sailing from tree to tree issuing its blood- curdling hawk call.
Maybe the sassiest behavior, however, is the species' tendency to land right above me and knock acorns all around me. One even pooped on my shoulder.
Well, with the Creator's obsession for diversity, it's clear that "sassiness" can be considered an option.