Tingle is the son of the guy in MM that wants your to give him pics in the same shack you have the boat rides in.

I suppose the whole cuccos getting mad at you when you damage it too much is an easter egg (except TP where you get to control it XD)

The fact that you can catch the Fishing Pond Owner's hat in OoT and then lose it in the pond haha!

If you dance with Kamaro's Mask in front of a Scarecrow, then the Scarecrow will dance with you.

If you wear the Captain's Hat in front of Igos du Ikana, He briefly mistakes him for Captain Keeta.

As for Gossip Stones:
-You can hit them with the Megaton Hammer and they'll flatten out for a few
seconds them pop back up and laugh at you.

-You can use magic on them and they'll spin around while stretching then
laugh at you.

-You can use a bomb or bombchu on them and they'll start flashing them
shoot off and if there's something above them they'll blow up when they
hit it.

-If you play the Song of Storms or the Sun's Song (where time does pass)
in front of a Gossip Stone you'll get a fairy spirit that will fill up your
life and magic.

-If you play Zelda's lulaby, Saria's song, Eponia's song, or the song of
time you'll get a regular fairy that fills up just your life.