Pair of Poplar Hawk-moths. Large moths with a wingspan of 65-92mm but, like most moths, harmless. UK flight time May-Aug.
The photos of the Poplar Hawk-moth below were taken by Terry Hobbs:
Showing the moth's normal resting position with its lower body curved upwards.
The docile moth on his finger . . .
and on a basket of petunias.
Poplar Hawk-moth Caterpillar:
The Poplar Hawk-moth Caterpillar eats poplar, willow, apple and some other leaves. Like several hawk-moth caterpillars, it has a spike at the tail end.