Oh, just realised it's got to be something to do with them trying to teleport to you...
Jeffry R. Fisher added a comment - Yesterday 11:28 PM
From a programming standpoint, simply changing to an inequality is the minimal fix. However, from a gameplay standpoint, having such a specific, 38-biome list makes no sense. What if the achievement were any 38 (or other arbitrary number) of distinct biomes? Why should an achievement have such a specific list? Visiting 38 different biomes is quite a feat!
The 38 biome list is the same as the left hand column of this table: http://minecraft.gamepedia.com/Biome#Biome_IDs, except for FrozenOcean and Extreme Hills Edge which don't generate. I was thinking it should be the complete list with all variations (because that's what I did), but then that would be basically impossible to achieve without external mappers.
Also, my world is about 1.4GB now and still doesn't have JungleEdge M, can anyone confirm if that generates or not?
Confirmed fixed, thanks. Screenshot from a mostly legit survival world, my stats file shows the following 56 biomes, although I gather from the comments here it wasn't necessary to get every variation...
"Beach",
"Birch Forest Hills M",
"Birch Forest Hills",
"Birch Forest M",
"Birch Forest",
"Cold Beach"
"Cold Taiga Hills",
"Cold Taiga M",
"Cold Taiga",
"Deep Ocean",
"Desert M",
"Desert",
"DesertHills",
"Extreme Hills M",
"Extreme Hills",
"Extreme Hills+ M",
"Extreme Hills+",
"Flower Forest",
"Forest",
"ForestHills",
"FrozenRiver",
"Hell",
"Ice Mountains",
"Ice Plains Spikes",
"Ice Plains",
"Jungle",
"JungleEdge",
"JungleHills",
"Mega Spruce Taiga",
"Mega Taiga Hills",
"Mega Taiga",
"Mesa (Bryce)",
"Mesa Plateau F M",
"Mesa Plateau F",
"Mesa Plateau M",
"Mesa Plateau",
"Mesa",
"MushroomIsland",
"MushroomIslandShore",
"Ocean",
"Plains",
"River",
"Roofed Forest M",
"Roofed Forest",
"Savanna M",
"Savanna Plateau M",
"Savanna Plateau",
"Savanna",
"Stone Beach",
"Sunflower Plains",
"Swampland M",
"Swampland",
"Taiga M",
"Taiga",
"TaigaHills",
"The End",
This is still happening for me in 14w06b.
Yeah it's a dupe of that, I had tried searching but didn't find it.