I even designed a top-down card to represent the Sphere Grid
You can only access dungeons or progress through them if you play a card with the ability venture into the dungeon. Wizards revealed a few common creatures with the ability as well as a few legendary adventurers
Its just as powerful as it sounds
The following year, however, Tempest brought the original Best Fatty of All Time, Verdant Force
If the chosen permanent is a copy of something else (for example, if the chosen permanent is another Clever Impersonator), then your Clever Impersonator enters the battlefield as whatever the chosen permanent copied
Pantlaza's Discover ability means that each dinosaur you cast has the potential to trigger a cascade, letting you fetch up one or potentially more other random dinosaurs from your deck (worst case scenario you hit a mana rock or something)