The key parts of an overrun are mana value, trample and lethality
It not only provides the mana to ramp into larger threats, but also turns them into cantrip creatures as they enter, though that card draw sometimes works for your opponents, too
Creature - Cleric Phyrexian Color tag templates(None) Tatyova, Benthic Druid Landfall Whenever a land you control enters, you gain 1 life and draw a card
This Simic card is just another generically powerful Simic creature in the vein of Aesi, Tyrant of Gyre Strait and Koma, Cosmos Serpent that fails to meaningfully distinguish itself from its predecessors
I particularly like this on a Commander with a low power and toughness so it can kill in four hits of Commander damage, and it will recur as well as the Commander if someone takes it out
I did the light and shadow and texture by using the dodge and burn tools in Photoshop with a stock textured brush