When do you start getting earthquakes and cracks in the ground?

[CrazyDiamond]

I have none of that. And also no crab. Where is the red crab?

[Yalliria]

I got a popup telling me that a villager found a crab and wants to name it. I said he could keep the crab and then I had this red crab,

[Grim4U]

I got the crack to show up at the bottom of the clothing hut when "The Idol" event popped up and i chose to pull it from the ground, but the red crab i don't know what that is.