l adopted three animals spontaneously. first the most aggressive labrador ever seen, guy working in shelter was telling about him, that he was mostly in cage to keep other dogs safe, next day he was mine. he lived happy life, chew all wooden furniture, slept next to me every night, swim in lake every day and died peacefully. took two blind kittens from street, now they are beautiful fluffy girls. couldn't save their eyes, infection was too serious, but they are beautiful, they like hunting, bringing ugly bugs from balcony, sitting on keyboard when l'm working etc. :) so, i want to say that spontaneously taking animals can work, but only if you are not caring about materialistic things, like expensive furniture or vases :) and if you have some experience.

All three of my cats were spontaneous rescues. And they worked out wonderfully! :)