I changed the size of the card and panels to be a little larger (3"x3") than the original just so I'd have an easier time cutting and assembling my critters. I also cut the first top panel longer than the rest so it would completely hide all the panels underneath and allow me space to add a sentiment to the front of the card.
With the additional and larger panels, the overall size of the card turned out to be 7" tall and 4-1/4" wide. To avoid having to increase the width of the card by too much, I decided to staple the holding strip onto my card instead of using brads. Then to conceal the staples, I glued on a piece of patterned paper the same size onto the holding strip.
Then by increasing the length of the sliding strip to 12"and adding an extra scoreline at 5", I was able to add an additional panel to my card.
All critter images (bear, owl, poodle, & cupcake) are from the Create A Critter cartridge. "16" was cut using the Sizzix Fun Serif number dies, and die cut alphas are Quickutz Mini Maggie. Square & scalloped square are Nestabilities, and the font for the sentiment is LD Miss Rose.
Had fun playing around with this and altering the original waterfall card. Recently, I saw another where the panels were ovals instead of squares! Gonna have to give that one a try too!