Impressively, it features 9 cards that appear in 5% or more of the EDHRec decks they are eligible for
Beyond saving a Creature in peril, if you have a creature with an Enters trigger you want to double up on, Flock Impostor has you covered
However, I'm hopeful we do not need to do this, as it would need to be a fairly extreme circumstance
However, as we all know, a much better and more likely use for this cheap artifact is as fodder for
Weekly MTG
You can play a land only during your turn and only if you have an available land play remaining.) Normally, playing a land can only be done as a sorcery, but the madness trigger circumvents that timing restriction, allowing you to play the land even if it's not your main phase and even if the stack is not empty