Shaxs called Rutherford "Baby Bear".
Baby Bear was a nickname that Lieutenant Shaxs gave Ensign Sam Rutherford while they were serving together on the USS Cerritos during the 2380s. Rutherford, in return, called Shaxs Papa Bear in informal settings.
In 2380, there was a brief period when Rutherford thought about transferring to the security division to serve on the security team under Shaxs. During this brief change in his career, Shaxs proudly welcomed him to his "bear pack" with open arms, calling him Baby Bear. (LD: "Envoys")
Later that year, when Rutherford joined Shaxs on a mission that involved the rescue of a prisoner of the Romulan Empire, Shaxs told Rutherford "Great work nerve pinching those Vulcans, Baby Bear." (LD: "Veritas")
Not long after that, just moments before saving Rutherford's life aboard a Pakled ship, Shaxs sacrificed his life to save Rutherford's, but not before saying his final words: "Hang in there Baby Bear!" (LD: "No Small Parts")
By 2381, Shaxs began serving aboard the USS Cerritos again, and while Beckett Mariner and Brad Boimler weren't all that surprised by the fact that another bridge officer simply came back to life, Rutherford was curious to know how it happened, as he felt guilt about his death, believing it to be his fault. Because of this, he approached Shaxs on a turbolift and asked him. Shaxs called Rutherford "Baby Bear" once more, and put his hands on his shoulders and told him exactly what happened, but not before warning him that he might not want to know the horrific story. (LD: "We'll Always Have Tom Paris")
After Ensign Brad Boimler suggested that they eject the warp core to destroy the Texas class starships just as Shaxs had mentioned, Shaxs was very proud of Boimler, and he welcomed him to the bear pack and called him Baby Bear as well. (LD: "The Stars At Night")