Finally got back out on the lake today.
I’m not sure where the creature was that created this, but I’m sure she’s around somewhere:

The lake itself might not be considered a “creature”, but it does change over time. This area used to have navigable water all the way up into the trees in the background, but over the last few months has accumulated a good bit of silt:

which has formed an almost square sharp shelf where the water runs out of the delta:

Fortunately, these mud flat areas are very productive, and many take advantage of that:

A group of Red-Winged Blackbirds was working the trees along the lake:

Probably taking advantage of all the Mayflies hanging around:

Common Grackles were also getting a piece of the action: