Vanishing Woods - Anastasia Evans - Bog

Grandmother Squirrel has given her farewells to her grown daughter and intends to retire in her empty nest before the harsh winter her homeland is known for arrives. At this moment it is revealed that the tree she's made her home in for so many years is a titanic merman buried in the ground. The Tree offers to take her on a journey to the sea to avoid the cold and live to look forward to one more spring. Grandmother accepts, and Tree carries her across strange lands she's never before seen, swimming through the soil like water.