Alfonso

Alfonso's catchphrase is "it'sa me" (without a hyphen), which is a reference to Mario's well-known greeting, "It's-a me, Mario!" (first heard in Super Mario 64). In previous Animal Crossing games, Alfonso starts out with the "big bro's shirt" -- a red T-shirt with Mario's "M" logo on the front.

Money rock

One rock per day will give you bells when you strike it with your shovel. For a limited time, more and more bells will pop out with each hit. After four hits, the classic Mario 1-Up jingle will play for each bag of bells you knock out.

Squid

After you catch a squid, one of three possible quotes will appear. One quote refers to the squid-like Blooper enemies first seen in Super Mario Bros.: "I caught a squid! Do they...not actually 'bloop'?"

Gullivarrr

Gullivarrr, the pirate version of Gulliver, might mention Captain Syrup (from the Wario Land series) after you agree to help him: "Really?! Why, you're even sweeter than the famous Captain Syrup—but without her double-crossin', I hope!"

Super Mario items

Items from the Super Mario series were added to Nook Shopping on March 1, 2021, as part of Nintendo's Super Mario 35th Anniversary celebration. Players who downloaded the Version 1.8.0 update (released February 25, 2021) received the "Mushroom mural" wallpaper as a free gift.

More info coming soon...

Thanks: Toad