In order to cross yet another waterway, the Zoombinis must take the help of enormous toads (voiced by Frank Welker). The toads are evidently willing to help Zoombinis cross, at least for a while, because each will bring 2 Zoombinis across even though this requires them going back once they have already crossed the river once. However, the toads are extremely particular about the paths they take, for whatever reason: They only follow paths that correspond with the tattoos on their back. Sometimes crabs migrate up this area and intersect with the paths of the toads.
In the second difficulty, Bruno the Shape Swapper appears and drops his magic wand for switching lilly pads, and in the third and fourth difficulties, crabs cross the lily pad patch from north to south, perpendicular to the paths of the toads and also following paths based on their back tattoos. Every time the Zoombinis leave, Bruno changes all of the lily pads, hence why they are different at each crossing.
How to SolveEdit
There are essentially three types of frog: those whose tattoo indicates color, those whose tattoo indicates "flower" shape, and those whose tattoo indicates lily pad shape. The last of these categories should be avoided in higher difficulties, because the crabs move based on lily pad shape, and thus any path you make for your toads will screw up a path for the crabs.
In the first difficulty, you simply need to look for the paths that are already there in front of you. It is a good idea to trace them carefully before you put a toad on the line, though, because the toads never get back off the lily pads if you place them on a dead-end path.
In the second difficulty and on, you need only look for nearly-completed paths, because you can use Bruno's magic wand to swap in the lily pads that you need.
In the third and fourth difficulty, however, it is important to be careful to leave the paths of the crabs intact, or they will cause serious problems. For this reason, avoid using lily-pad-shape paths and, when swapping, always swap in a lily pad of the same shape that you swap out. The sound of the crabs moving was done by recording a saw cutting through wood and then increasing the sound to a higher pitch.
Skyscraper "The Man" Jackson 02:16, May 30, 2012 (UTC)