Several animals can kill chickens and will kill chickens.
Some animals that can and will kill chickens are animals such as dogs, a coyotes, a fox, a bobcats, chicken hawks, hawks, owls etc.
If the chicken is dead but still there then the animals that likely killed the chicken are dogs, coyotes, foxes, bobcats etc.
If the animal is missing then it could have been carried off by an animal such as chicken hawks, hawks, or even owls.
But even a dog or coyote or bobcat could kill and carry off the chicken as well but just not in the air.
If you have something killing your chickens I would recommend putting up a video camera or even a game camera to see what is actually killing your chickens.