Effective with the November 16 downtime, Peregrine Drake will be banned in the Pauper format on Magic Online.
Erik Lauer from Magic R&D had this to say on the reasoning behind the change:
Before Kaladesh, R&D looked into whether to ban Peregrine Drake. At the time we were discussing changes, Izzet Drake had been about eleven percent of the competitive metagame over the previous month, though it varied from week to week. It was the strongest performer, but not by a large margin. The metagame over that month was still diverse, so we decided to not take any action.
Since then, the deck has increased in performance. Its presence in the competitive metagame has doubled, and its win rate has also increased. It is now significantly harming the diversity of the competitive metagame. For those reasons, we are banning Peregrine Drake from Pauper.
Magic formats typically only have changes to the banned and restricted lists with each of the four major set releases each year. However, since Pauper is only a format on Magic Online, we have the ability to more quickly make changes in ways that affect all players since the legality of changes can be universally enforced. This differs greatly from the paper game, and this change should not be considered typical. It was, however, an opportunity for us to leverage the flexibility and data of our digital platform.
Given R&D's desire to make this change, we were able to implement it on Magic Online with the November 16 downtime rather than forcing players to play a less fun format until Aether Revolt.
The Pauper Friendly League currently in progress on Magic Online will close on November 15 at 10 p.m. PT and end on November 16 at 3 a.m. PT. A new Pauper Friendly League will begin after the November 16 downtime with the ban taking effect.