Change the BoxMesh to a SphereMesh
Rename the MeshInstance3D to Base
Duplicate and Scale the Mesh Instance
Press CTRL+D to duplicate the node and use the move tool to move it up.
Use the scale tool to make it smaller than the sphere below it.
Repeat the process for the Head.
Create a BoxMesh for the arms.
Rename the parent node: Snowman.
Now we can create multiple instances of snowmen.