A lost frog. It was hiding behind the plant pots by our front door, in a wilderness of paved & gravelled front gardens in a street of terrace houses. Damned if I know how it got there. We took it to a better place, i.e. our allotment, to enjoy the pond, abundant cover, & plethora of edible invertebrata.
I opened the container in which we'd carried it & handed it to Mrs B to release it. She said "How should I release it?" - just as, with perfect timing, it took matters into its own claws & leapt out, straight into the pond.
PS. I understand that moving amphibians is illegal in general, though allowed to rescue 'em, e.g. from being run over. Considering that I was in the process of destroying its hiding place when I found it, I think I rescued it by moving it.