When a St. John's-area tree company unloaded a new shipment of shrubs last week, it found a tiny stowaway aboard, and one with a fascinating appeal.

The plump, long insect was about 3.5 centimetres in length, and considerably longer than a typical caterpillar.

"He's probably one of the biggest ones you'll find in North America," said Chris Swyers, owner of C.D.'s Trees in Logy Bay, describing the wiggling insect that a student discovered while unpacking a shipment of dogwood shrubs that had arrived last Thursday from Ontario.

The insect was identified as a cecropia moth caterpillar, which is seldom seen in Newfoundland. Not long after the insect arrived, it began its process of transforming into what is expected ot be a spectacular moth.

"On Saturday, he was doing laps around the aquarium, looking for a place to set up housekeeping," Swyers told the St. John's Morning Show.

"On Sunday morning, when we found him, he was wrapped in almost a pure white silk cocoon, and attached himself to a lot of the twigs and leaves that were there."

The insect was still wrapped in a cocoon on Wednesday, as Swyers prepared to show the cocoon to curious agricultural scientists.

The moth does not pose a threat as an invasive species, but has fascinated those who have had a look, Swyers said.

"It was a rare opportunity for us to have a look at something like this and watch it happen," he said.