Over the years I have heard many terms/phrases for when someone is stuck with a seemingly impossible task: they're up a creek, caught between a rock and a hard place, they are toast (or toasted), doomed, etc.
For me and my office-mate, it's all about panthers. A deadline came up that, put mildly, scared the living daylights out of me, and I may have gone a little crazy. At the same time, my office-mate was fighting with some software that was doing everything in its power to flummox her and deny her the right to sanity. It won, for a bit.
We were so lost for words that the next natural thing to come to mind was panthers. It was funny - made us laugh and let us get back to the important stuff we were trying to do. But it kept growing and growing... and now, every time we are stressed out about a difficult or monumental task, all we have to say is "I'm totally panthered." We've even spread the word to a few of our friends.
Various indicators of panthered-ness have appeared in our office: small stuffed animals, sticky notes counting the number of panthers in the room (invisible, obviously), and most recently, little panther charm necklaces that we wear when in super dire need. One friend bought us figurines of other big cats (because he couldn't find any actual black panthers), so I have a tiger living on my desk, and my office-mate has a leopard.
Some days, it's not so bad to be totally panthered anymore. :)