Now keepers say the cat is in mourning after her 42-year-old pal died of old age at Berlin Zoo in Germany.
Keeper Andre Schule explained: "She had been ill for some time and in a lot of pain. She was one of the oldest bears alive in the world and had lived far longer than she would have done in the wild."
"But poor Muschi is inconsolable. They shared a bed together but it'd be too dangerous to let her back into the bear enclosure without her friend there to protect her," he added.