NARWHAL

Marine mammal with an ivory tusk (7)

Solution has appeared in 2 crosswords (1 across and 1 down):

• Quick crossword No 16,563 — 2023-06-06 23:00:20
  15D: Arctic mammal with a spiral tusk (7)
• Quick crossword No 15,935 — 2021-06-02 23:00:02
  12A: Marine mammal with an ivory tusk (7)