What does the cryptic crossword clue "A potentially strange pet, old boy (5,4)" mean?

The wordplay uses an anagram. anagram of PETOLDBOY ("pet, old boy") [anagram: "potentially"] = BLOODTYPE The answer is BLOOD TYPE.

A potentially strange pet, old boy (5,4)

Times Cryptic #28800 | 8 Down | 2023-12-30 flower