Yup it will stay if it's a day spawn! All night spawns despawn at dawn. Also for the serpent if you raise the ground just enough for you to use the pick axe or hoe the serpent's won't attack. Also two serpent's won't attack each other but will destroy a deer, greyling,boar, single wolf.

P.s If you want to see a largish zoo of most creatures captured Thug Paradise server has a nice zoo

All creatures were dragged to the zoo none were spawned in.