Decorate mini cakes. Prepare three decorating bags with tip 199. Fill separately with light, medium and dark green icing. Using pull-out star technique, pipe cacti in various shades of green.
Prepare decorating bag with tip 18 and light magenta icing. Pipe small star on tops of cacti.
Prepare decorating bag with tip 2 and white icing. Using pull-out dot technique, pipe needles on ridges of cacti.
Sprinkle graham cracker crumbs between cacti.