spring out at (someone or something)
To emerge (from something) and leap or pounce in the direction of someone or something. The attacker sprang out at her from the shadows, but she managed to incapacitate him with a punch to the throat. The mouse sprang out at bits of food that feel in front of its mousehole.
spring out at someone
to jump out at someone. A grasshopper sprang out at me when I peered into the hollow log. I was afraid that something would spring out at me, so I opened the cellar door carefully.