The phrase Never Give Up! comes to mind here :)

The one with the frog halfway in this bird's throat and he's grasping its neck so he can't go down any further? Yeah well this prey is entirely in the hydra's throat, and once you're fully engulfed by the esophagus it's over - you can't resist those powerful throat muscles forever!

So yeah... I had this idea of a hydra head struggling to get a nice, big, and defiant morsel down its throat, with one of its partners chortling in amusement and doing nothing to help the situation ^^