The end and the beginning
A moment of simultaneous fascination and sadness upon seeing this phenomenon for the first time. Such is the natural world and all its many convoluted, connected pathways.
I believe this is a catalpa sphinx moth caterpillar that has been parasitised by a braconid wasp...seen here attached to the caterpillar are the wasp pupae, or cocoons that have finished feeding and are metamorphosing into adults.
I noted that the caterpillars (although often stunted and slow to react), looked alive with their extra baggage of cocoons - but I learned that the damage had been done and their days were numbered.
Body length of caterpillar 50mm