What is this bearded bee/fly bug?

[PortlandHen]

Hey fellow gardeners,

Do you know what this bug is? I'm not worried about it and it's leaving the chickens alone, but I'm curious. It has a beard! It seemed a bit aggressive so I took a photo and left. It's about an inch long and was eating a dragonfly?

Thanks!
Chelsey

 

[Tina Shelton]

He's a scary little guy!

 

[lazy gardener]

Check out this: http://aggie-horticulture.tamu.edu/galveston/beneficials/beneficial-27_robber_flies.htm