Possible Clues:

• Muscular vagabond embracing nymph?
• Caterpillar stage, for example
• Animal in immature state
• Grub from river running through soft rock
• Newly hatched stage
• Early stage of creature
• Liberal Harrovian periodically shows form of immaturity
• Cricketer is about five, so form not yet developed
• Grub found where river enters volcanic rock
• Grub of regular variety