If increased accuracy is out of the question (theres a total of 56% between 5 items that I know of), perhaps maybe an AA (with a hawk pet, of course) that gives a % chance to score a double hit (as in 2 arrows), in 3 steps of increasing %, lets say a billion, two billion, and fifty billion! haha jk maybe 2, 5, 10% for 3, 6, 9 aa's. From a roleplay perspective maybe the second hit is really the hawk swooping down and clawing with its talons.
Or perhaps a non-combat related one: Make an Eagle pet instead of a hawk and give all the effects of Spirit of Eagle (self only: Movement increase, See Invis, Levitate, Infravison - maybe a sta regen effect too) whenever it is summoned. It can be immune to damage (AoE may take it out in one hit) or not if its easily castable. "But why SoE? we can cast it!" you may say, well how about making this castable indoors, and just be like a worn effect (so it wont take a spell slot and cant be dispelled). This way we'll have a cool hawk pet, it wont be overpowering (just convenient) so you dont have to change anything else, and it'll just be plain fun. Oh and from a RP perspective, the 'hawk eyes' for see invis and infravision, maybe the hawk grabs us and flies with us for the levitate and movement. 9 aa's single purchase would do the trick.
Oh and for a graphic... the only one i know of right now is a GRIFFON! That would work =)