I was looking at the map of my seed, and i found this super sized mushroom island that looks quite a lot like a fish, unfortunately can't send a video of it for some reason
It is around 1200 blocks in lenght
how it is in 3 different oceans creates a nice contrast
it is in version 1.21.4
i included both a pic from my map and from using distant horizons to try visualize it
the cords are 7800/72/-36666
and the seed is -1638294273747316921
by Ready_Tackle_1846