Aprils Fool is challenge #32.
This challenge changes all floor bosses to The Bloat, changes pedestal items and pickups to actually be something else, and displays your location as a random room on the map. Your goal is to defeat Mom's Heart, which is also The Bloat. Treasure rooms and Shop rooms are present in this challenge.
- All pedestal items appear to be a different item until they're picked up. The item you actually acquire is still one you would normally get (Angels will still drop Key Pieces, Mom will drop The Polaroid and The Negative if they are unlocked).
- This means though that you can't decide which items to pick up based on their appearance, just as with Curse of the Blind.
- Pickups (coins/hearts/bombs/keys) always give a different pickup than they should. Coins give health, bombs or keys, bombs give health, coins or keys, and so on.
- Because of this, it's very hard to accumulate coins - you will be getting about one coin for every three or four non-coin pickups you take.
- On the other hand, it can have a cascade effect as pickups have a chance to turn into Soul, Black and especially Gold Hearts, which when depleted will spawn more coins giving a chance to get those hearts back immediately.
- All active items, pills, cards and runes have a random effect upon being used. A lucky penny won't give you any money, but still will have the +1 luck effect.
- It's potentially dangerous to use cards as they can trigger the Suicide KingKills Isaac and spawns lots of pickups, items, and/or chests in the same room. effect.
- Additionally, Stoneys have a chance to become Cross Stoneys, making them significantly harder to deal with.
- Randomness can be the key factor to surviving this challenge, as sometimes coins will actually give Soul hearts, black hearts, and crucially, gold hearts. This means that if you get lucky and come into a lot of coins, you have a chance of easily and quickly increasing your health (in addition to potentially getting gold hearts), and the gold heart synergy will spawn more coins, resulting in potentially more health, allowing you to take some damage with impunity.
- When dimes or nickels are picked up, they will act as 10 or 5 of the pickup they act as respectively, which can lead to gamebreaking results such as getting 5 gold hearts at once.
- It is possible to use a Swallowed PennyUpon taking damage, Isaac drops a penny. along with a sacrifice room and the frequency of Gold Hearts to generate infinite coins. This also will end up triggering many of the sacrifice room's effects, such as transporting Isaac to Dark Room. The challenge can still be completed by defeating The Bloat at the end of the Dark Room stage. This can be done as early as the first floor. This may or may not be a bug.
- Be wary of using active items as it is possible to get undesirable effects such as Glass CannonWhen used, reduces Isaac's health to half a heart (including soul and black hearts) and fires one large piercing spectral tear that does a lot of damage. The damage done by Glass Cannon scales with Isaac's damage (at base damage it does 45 damage). or Plan CKills all enemies in the room, then kills Isaac three seconds later..
- Active items with a short charge time like Butter BeanIsaac farts and pushes back nearby enemies. can be used frequently for random effects, while getting a zero recharge item (like Kamikaze!Creates an explosion in the same area as Isaac, dealing half a heart of damage to him and also damaging all enemies caught in the blast radius.) and using it rapidly can result in a game-breaking run.
- The scrambled map allows all secret rooms to be found for free easily. The highlight of where you are on the map does not reflect your location but it will only show spots on the map which actually are rooms even if they have not been uncovered yet, including secret and super secret rooms.
- Be very wary when using cards, as they could randomly activate a Suicide King effect.
- Although items have changed their appearances, the item Isaac gets still belongs to its item pool. Thus, it could be treated as Curse of the Blind as usual.
- Counterfeit PennyGives a 50% chance of increasing the value of every coin pickup by one. has a chance to grant coins upon picking them up, making it easier to accumulate coins.
- Golden Hearts are extremely useful as they will drop random pickups (which have a chance to be more Golden Hearts and Soul/Black Hearts) when Isaac takes damage.
- Pills will always show their true effect in their name after being used, and the narrator will always state what the effect actually is, meaning that setting the narrator to always activate can be helpful.
- This challenge's effect of changing item appearance is similiar to the April Fool's 2016 daily challenge.
- All bosses are replaced with The Bloat, this is a reference to the exceptional hatred some fans express toward this boss.
- Cross Stoneys are exclusive to this challenge and were added in Booster Pack #5
- Ironically, Cross Stoneys were revealed on April 1st. 
- Similarly to The Bloat's inclusion in this challenge, Cross Stoneys are a nod to the community's generally negative reaction to Cross Stone Shooters added in the previous booster pack.
| Mom Unlocks
|The WombDefeat Mom for the 1st timeThe HarbingersDefeat Mom for the 1st timeA Cube of MeatDefeat Mom for the 1st timeA HaloDefeat Mom using The BiblePuristDefeat Mom for the first time
||XXXXXXXXLDefeat Mom for the 1st timeSPEED!Defeat Mom for the 1st timeHave a HeartDefeat Mom for the 1st timePRIDE DAY!Defeat Mom for the 1st timeOnan's StreakDefeat Mom for the 1st timeThe GuardianDefeat Mom for the 1st time
||Aprils foolDefeat Mom for the 1st time