They got removed in I believe the Neapolitan update. Monsnow, Flurry Jr, and Duke of Flakes got scrapped in favor of Williwaw, Wendy, and Prong.

Monsnow is still in the game but only in boss challenge rooms

引用自 chatteringteethdemon：

Monsnow is still in the game but only in boss challenge rooms

so is for duke of the flakes and flurry jr

引用自 salo_1420：

引用自 chatteringteethdemon：

Monsnow is still in the game but only in boss challenge rooms

so is for duke of the flakes and flurry jr

Monsnow appears in the Boss Challenge room with his Glacier mechanics, but Duke of Flakes/Flurry Jr only have their sprites; their mechanics work the same as in the vanilla game. The decision to let Monsnow keep his mechanics and remove them from the other two was was done simply because Monsnow was the better polished boss of the 3, and it felt wrong to just remove a pretty decent boss completely. Flurry Jr and Duke of Flakes were.....not really good bosses compared to Monsnow.

引用自 Grynn：

引用自 salo_1420：

so is for duke of the flakes and flurry jr

Monsnow appears in the Boss Challenge room with his Glacier mechanics, but Duke of Flakes/Flurry Jr only have their sprites; their mechanics work the same as in the vanilla game. The decision to let Monsnow keep his mechanics and remove them from the other two was was done simply because Monsnow was the better polished boss of the 3, and it felt wrong to just remove a pretty decent boss completely. Flurry Jr and Duke of Flakes were.....not really good bosses compared to Monsnow.

oh alr thx for letting me know