This is a frog tribal/self mill deck where i tried to build within a budget, since where i live, MTG cards are too expensive. You can end up making some changes, like putting a cyclonic rift for board clear or a rhystic study for better draw engines (even tho i don't recommend it, because you want to mill your combo pieces).
The strategy is pretty simple, you need to mill your combo pieces while Grolnok is on the battlefield under your control. So, for the game start, you don't want to draw your win conditions or combos, so you got to mulligan away the following cards:
Cephalid Illusionist
Hermit Druid
Laboratory Maniac
Thassa's Oracle
Jace, Wielder of Mysteries
Basalt Monolith
Mesmeric Orb
Lightning Greaves
Since Grolnok only lets you cast permanents from exile with croak counters on it, you are going to want to keep some useful sorceries and instants in your hand. Any counterspells, mill options and specific ramp spells you are going to want to keep.
The playstyle here is kinda peaceful, you don't want to aggro your opponents too soon because most part of the game you will probably be vulnerable, so, cast Grolnok as soon as possible, and keep sliding some soft hits on your opponents just to activate it's triggered ability if you already have a good hand to defend your board and/or started with Traumatize/Cut Your Losses, because you want to mill a combo as soon as possible. If your hand isn't good enough, you want to avoid milling early in the game, because you can end up milling some important sorceries and/or instants.
As soon as you have a combo on exile with croak counters on it, you need to be sure that no one will get to your combo and screw it. So. it's important having counterspells or, something like Heroic Intervention, Autumn's Veil etc.
The combos you have are the following:
1- Cephalid Illusionist + Lightning Greaves -> You need both on the battlefield under your control, and an additional creature. Cephalid Illusionist has "Whenever Cephalid Illusionist becomes the target of a spell or ability, mill three cards.", and Lightning Greaves has an equip cost of 0 mana. So, you are gonna keep equiping the Greaves to Cephalid Illusionist and to another creature, until you mill a win condition.
2- Hermit Druid + Any Win Condition -> You need your deck free of basic lands. The deck has a total of 12 basic lands, so you wanna keep tracking of all the basic lands. Hermit Druid has "Pay a green mana and tap it: Reveal cards from the top of your library until you reveal a basic land card. Put that card into your hand and all other cards revealed this way into your graveyard.", so, if you have no basic lands in your deck, you will mill the whole thing, and soon, a win condition, this way, winning you the game.
3- Basalt Monolith + Mesmeric Orb -> You need both permanents on the battlefield under your control. Mesmeric Orb has "Whenever a permanent becomes untapped, that permanent's controller mills a card." and Basalt Monolith has "Basalt Monolith doesn't untap during your untap step. Tap it: Add 3 colorless mana. Pay 3 colorless mana: Untap Basalt Monolith.". So, basically, you will keep adding 3 colorless mana and using it to untap the Basalt Monolith itself, while triggering Mesmeric Orb everytime you untap the Basalt Monolith, milling this way, your whole deck, and eventually a win condition, winning you the game.
The win conditions are:
1- Thassa's Oracle
2- Jace, Wielder of Mysteries
3- Laboratory Maniac
I already tested the deck a lot, and it's weaknesses are usually aggro decks, because you need a little bit of time to build your strategy, but eventually your learn how to deal with, that's why you have some fog effects on it, like Spore Frog and Haze Frog. Always remember, commander is a very political game mode, so talking is one of your best options.
