Brokkos, Apex of Forever | Infested Thrinax | Pitiless Plunderer (and one other card)

Cards

Cast
Infested Thrinax by paying ({3} magic symbol) ({B} magic symbol) ({G} magic symbol) .
When
Infested Thrinax enters the battlefield, it triggers, causing you to create a number of 1/1 Saproling creature tokens when a nontoken creature you control dies.
Activate
Ashnod's Altar by sacrificing
Brokkos, adding ({C} magic symbol) ({C} magic symbol) .
When
Brokkos dies,
Infested Thrinax and
Pitiless Plunderer trigger.
Resolve the
Infested Thrinax trigger, creating six 1/1 Saproling creature tokens.
Resolve the
Pitiless Plunderer trigger, creating a Treasure token.
Activate
Ashnod's Altar twice by sacrificing two Saprolings, adding ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) .
When the Saprolings die,
Pitiless Plunderer triggers twice, creating two Treasure tokens.
Activate three Treasures by tapping and sacrificing them, adding ({UB} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Cast
Brokkos from your graveyard for its mutate cost by paying ({2} magic symbol) ({UB} magic symbol) ({G} magic symbol) ({G} magic symbol) , putting it on top of a Saproling.
Repeat from step 3.

This combo has been estimated to be Exhibition (Bracket 1+).