Mimic's life as a pet

Mimic is a shapeshifter, a dangerous gender-less blob like creature that can devour anything by absorbing it and shifts into any life form to lure in it's prey.

15 years ago it was caught by mister Mortell and kept as his pet.
It now lives with him and his growing up son Kaiden, who is blissfully unaware of the potential dangers of living with such a being.

Updates will be very slow.
I know how this one will end but I'm kinda stuck on how till fill the story up in the middle.