Watch the moment as an adorable little baby boy starts to 'growl' while he plays happily on the floor. The enjoyment this toddler expresses after discovering the sound will melt the heart of the most hardened viral video aficionado.

This uplifting clip shows how the tiny-tot begins to enjoy his new sound as a smile stretches across his adorable face.

At first he is unsure about the sound but continues to experiment with it coming to eventually own the guttural roaring noise.

Not to be put off from his task of playing on the floor, during his impersonation of a lion, this cute little tot hands the filmer one of his toys.

Footage shows a boy in a blue one piece sitting on the floor playing with a soft toy. He starts growling and then his face contorts as he gets used to making the sound.

The baby then crawls across the floor while making various versions of the sound with a huge smile across his face.

The tiny tot then hands the filmer a square soft toy.