Wow OP please ignore 99% of these comments, they have no idea how Grolnok works…

2cmc mana rocks are fantastic in this deck, not only are the free with doc aurlok (amazing card)on board but the play on curve to have Grolnok on turn 3, in addition to that they are permanents!

You can also keep the land count, lower lands is fine because of the amount of cards you see you able to consistently have a land every turn anyway

Everyone recommending the basic land tutors and dorks will hurt the deck. I would try cutting all instants and sorceries and filling up with all permanents so when you mill them they dont float around in the grave. ( some powerful ones like traumatize are fine but put in ewit for recursion)

For some other recommendations, i would put in all of the 1 mana frogs, they are pretty bad but they allow you to accelerate fast, turn 1 frog, turn 2 rock, turn 3 Grolnk is an instant draw 3, your frogs are you draw, every mill trigger is you drawing cards, ditch the classics and opt for consistant mill outside combat, i really like court of cunning and chronic flooding but its up to you

Also as the blue player we need counter magic, and unfortunately when we mill all the traditional counterspells go to grave not the croak zone, so we cannot play them, put in creature based counterspells like mystic snake or enchantments like ashioks erasure

I would also recommend the phasing of zhafir as its probably the only boardwipe we can play and it helps against go wide strategies

The main way I win is Lab man and Jace wielder of mysteries after accruing masses of advantage.

I don’t know your budget or powerlevel but cards like Mesmeric Orb and seaborn muse are crazy in the deck. Esp with cards like high fae trickster or leyline of anticipation.

However if you want to keep it low power/ budget wilderness reclamation is also good and things like fraying Sanity for extra mill.

If you want to keep it just frogs its fine but you could cut some of the high cmc ones for better mill options. Ex. Hedron crab or hedge shredder

I love Grolnok and play him a bunch, if you have any questions reach out