Hydra was a mythical beast with many heads; Hydra appliances are are multifunction designs that theoretically take up less space but end up just crowding countertops, and I couldn't decide if this should be in the Untreehugger or the Less is more category. Product Dose did a summary of a number of them and we wonder if they do any of their functions very well. The silliest is probably the 3 in 1 breakfast maker- a coffee maker, toaster oven and egg griddle all in one. Other versions included a toaster that has an egg poacher and a microwave with a toaster built in. We would think that a frying pan would be a bit more versatile and permit a bit more variety in your breakfast.
We did like the composters, both shown on TreeHugger here and here, and the countertop dishwasher looked interesting (although you could probably zip that many off in the sink in a minute or two) and since we think that small fridges make great cities, we found the fridge interesting if expensive. See them all at ::ProductDose