Two caterpillars - Series #17

Photo of two tropical caterpillars on a leaves. Left: Yellowish spiky caterpillar. Right: Gray furry caterpillar. Please help to identify the species. Thanks in advance. Related posts: * Furry caterpillar - Series #16 * Black caterpillar with white stripes and blue spikes - Series #15 * Black Yellow Spiky Caterpillar - Series #14 * Green caterpillar with fake eyes - Series #3