Lego Loch Ness Monster @ Disney Springs

I had to look closely to be sure this sea dragon in one of the lakes/ponds at Disney Springs was, indeed, made out of Lego bricks, but after a closer inspection, I can confirm that it is, indeed, legit Legos.  I have no idea if they build these big installations from ONLY bricks (meaning all the way to the middle) or if there is some form they use and apply bricks to the exteriors?  Do you Lego folks know?  Seems some folks use Duplos?  Or, as you'd guess, other structures.

I love how this Lego sea serpent/Loch Ness Monster is reminiscent of the topiary version from the Magic Kingdom and we always stop at the Lego store at Disney Springs.  Despite having that HUGE World of Disney store just a little bit further down the way, the LEGO store is always my kids favorite stop and where they typically put their (very limited) spending power.