Related Clues:

• Stage before metamorphosis
• Perhaps Caterpillar tractor's rear trapped in rock
• Maggot, say
• Immature bug
• Caterpillar, to biologists
• Six-footer to be found in Bear Valley
• Young animal sounding as if it may come from a volcano
• Immature form of life right in centre of volcanic discharge
• Early insect form
• Early form of atrioventricular valve
• Hot rock on radio for little six-footer?
• Prepupal phase
• Immature insect in mountain flower, right inside
• Caterpillar, say
• Maggot, e.g