Caladrius

The Caladrius is a snow white bird that was said to live in a king's bedroom according to myths and legends. It would stand by the king's bed and if he were sick, the Caladrius would take the sickness from the king into its own body. It would heal itself after that and the king would be healed too.

"There is a little white bird beside your bed, sire."
"Oh, that's my Caladrius. My little protector"