The squirrel first ran into a house in the southern town of Passau, leapt from behind on a 70-year-old woman, and sank its teeth into her hand, a local police spokesman said Thursday.
With the squirrel still hanging from her hand, the woman ran onto the street in panic, where she managed to shake it off.
The animal then entered a building site and jumped on a construction worker, injuring him on the hand and arm, before he managed to fight it off with a measuring pole.
"After that, the squirrel went into the 72-year-old man's garden and massively attacked him on the arms, hand and thigh," the spokesman said. "Then he killed it with his crutch."
The spokesman said experts thought the attack may have been linked to the mating season or because the squirrel was ill.