Many pictures of wildlife are found entirely by chance - because animals are so good at blending in to their surroundings. There have been a few times when I have taken a picture of an area that I felt surely had something of interest, so that I might look more carefully at the picture zoomed in - and found something entirely unexpected. There are some examples of this here.
Have to start with a lizard - this one is in northern Big Sur, CA, near the Pfeiffer home.
There is a green frog nestled in with the moss and leaves.
Herons are a master at blending into the background - standing absolutely motionless for tens of minutes on end.
Same wetlands - near the shore I became aware that various dragonflies and other flying insects would pass over the water and disappear. As much as I stared at the water, however, I could not see a thing. Finally I took several pictures of the area. The frog sort of jumps out to my eye in the photo above, and in detail below. I am pretty sure there is a second frog just to the right of the first, more visible in the enlarged image below, and possibly a third. Once the clearly visible frog settles back down in the water, with only his eyes showing, you can probably imagine how difficult it becomes to see any frog at all!
This barred owl did not look to be anything but a squirrel nest high in a tree - except that it was located out on a straight branch. Being nocturnal, and my being out during the day, the owl did not move for the half hour I spent trying to get a line of sight for a photograph. Except - in going through 100+ photos that I shot I could see that his head generally stayed in my direction - not quite asleep!
Snakes are not everyone's thing - especially discovering them hidden underwater!