Sean and Steph Mayo have made an adorable seedling Groot. Commissioned and sold for charity I'm not sure how the new owner is going to resist carrying it around at all times.
This baby Groot by Jack M. utilizes the leftover surround piece for some Lego foliage as part of the build. I really like the sand green mini figure hands as well.
Tyler's I am Groot is pretty fantastic as well. Utilizing whip elements to help make up the body was super clever.