As of right now, I feel the deck is ready for some hard play testing. Some very good suggestions have been made over the past few months, however, let's talk about some more recent decisions.
Fathom Mage: In the side board as of right now, although a very good card in this deck, I need to play around a little bit more and get a feel for the decks optimal play style and see how many, and how much of these are needed.
No fetch lands because Tropical Islands aren't basic.
Hooded Hydra: On side board because I feel that Chasm Skulker is a stronger card, but will still be play tested none the less.
Although I feel that Scourge of Skola Vale can in most cases be counter intuitive for the deck. (That being that it is a large target for hard removal that has the possibility to just fizzle out after killing a few of my creatures.) But, I have side boarded it because it can pop other creatures in response to removal and possibly spawn in a bunch of tokens in the process.
Otherwise, I see a few problems this deck may face, that being rush down decks, and flying decks. This deck has zero removal and may stalemate if Death Touch is present on the board. However, I feel this deck can do very well due to the huge creature it can create.
Also if this deck does interest you, various cards can be cheapened down to suit you needs.
Moreover, depending on the rule set for Progenitor Mimic, it may be absolutely horrific in the amount of shenanigans it can accomplish. If so, then cheaper cards like Followed Footsteps may be worth looking at.