Dumbledore the seal, who mysteriously appeared in a field in Merseyside last month has died.
The animal, found over 32km from the sea, had been placed in RSPCA care where it was hoped he could recover.
Unfortunately, Dumbledore continued to suffer from pneumonia and failed to regain his appetite.
In a statement the RSPCA said: "Sadly, despite all the highly-skilled care and attention he received from staff at RSPCA East Winch, Dumbledore the seal has died.
"While X rays showed he had no trauma from injuries and his severe pneumonia was being treated with antibiotic injections every day his appetite never fully returned."
"Sadly wildlife rehabilitation is particularly challenging and, of all the species the wildlife centres take in, seals are one of the more difficult to rehabilitate."