Prepeare the different colored jello separately according to package directions. Pour each color into a rectangular mold and refrigerate overnight until set. The next day, prepare the custard according to package directions. Cut jelly into cubes and scatter over the bottom of a heart-shaped mold.
Pour the custard over the cubes and refrigerate overnight. Rinse the raspberries and strawberries and pat dry. Hull the strawberries. To serve the pudding, dip the bottom and sides of the pan briefly in hot water, then invert the pudding onto a serving platter. Garnish with animal crackers and berries.