There are a total of 163 cards in the Cryptid Nation: Nightfall set, including 1 secret rare card (Old Scratch).
To complete the Cryptid Nation: Nightfall master set, you will need a total of 254 cards, which includes an additional 54 reverse holos and 37 non-holo gold rares (but does not include the secret rare card because there were only ~100 copies ever put into circulation).
There are also 7 token cards in Nightfall that do not have card set numbers on them.