From the New York Times, 5/24/1865
The Guard of Castle Thunder.
A huge Russian blood-hound, which for four years acted as the guard of Castle Thunder, has just been brought to this city by Mr. SIDNEY MUNN, who is now stopping at the Astor House. The hound is probably one of the finest specimens of the canine tribe that has ever been seen in this city. Jet black, standing over three feet in height, with a huge but well-proportioned head and body, and thews and sinews that might belong to a small bullock, he presents a very formidable appearance, and was doubtless an efficient guard to the rebel prison. His weight is said to be about 180 pounds. He was imported when quite young for the purpose of being trained to fight bears, in which amusement he soon became quite proficient. His owner states that within a year or two he has fought three pitched battles with full grown bears, and came off victorious in each. He formerly belonged to a Capt. ALEXANDER, who repeatedly refused $700 in gold for him, and matched him on one occasion in a bear-fight for $12,000. The animal is said to possess an amiable temper when not provoked. His appetite is good, six or seven pounds of meat forming an ordinary meal. He is certainly one of the greatest curiosities that has yet been imported from Richmond.