This simple mod adds more types of foxes to Minecraft.

The mod is available for both Fabric, Forge support is discontinued. Make sure you download the correct version!
These are complicated because of their spawning conditions (desert), and their different model. I am thinking about it.
If it's a common type with no special additions to vanilla's foxes then I might consider it.
No. However, vanilla already has a mechanic for it: breed two foxes and the baby fox will trust and actually protect you. It does not teleport to you and cannot sit on command.
No.
This mod adds 6 new natural types, making a total of 8 natural types. In addition, it adds two skins for foxes with certain name tags.
Foxes have a certain chance to have a specific type when spawned in a certain biome (this can be modified in a data pack, see below).

The most common type of fox, spawning in all taiga variants except snowy ones.
red/summon fox ~ ~ ~ {Type: red}
The most common type of fox in snowy biomes, highly dominating all other fox types there. Only spawns in snowy biomes.
snow/summon fox ~ ~ ~ {Type: snow}
A relatively common type of fox that spawns in all taiga variants.
black/summon fox ~ ~ ~ {Type: black}
A relatively common type of fox that spawns in all normal taiga variants. Has a rare chance to spawn in snowy taiga as well.
silver/summon fox ~ ~ ~ {Type: silver}
A rare type of fox that spawns in any taiga, yet more commonly in snowy biomes.
platinum/summon fox ~ ~ ~ {Type: platinum}
A rarer variant of the platinum fox, that spawns in any taiga, yet more commonly in snowy biomes.
gold_platinum/summon fox ~ ~ ~ {Type: gold_platinum}
A relatively rare variant that spawns only in old growth taiga biomes.
grey/summon fox ~ ~ ~ {Type: grey}
A common variant that spawns in all not-snowy taiga biomes.
cross/summon fox ~ ~ ~ {Type: cross}
A rare variant that spawns in almost any biome but is more common in snowy biomes or old growth tree taiga biomes. It does not spawn in the grove biome.
marble/summon fox ~ ~ ~ {Type: marble}
A alternate variant to the grey marble fox, that spawns in almost any biome but is more common in snowy biomes or old growth tree taiga biomes. It does not spawn in the grove biome.
brown_marble/summon fox ~ ~ ~ {Type: brown_marble}Naming a fox "FoxShadew" gives it this heterochromia skin:

The blue skin you see in the pictures exists in 1.2 and below, but has been removed in 1.3 for personal reasons. Sorry.
In case it wasn't obvious, foxes aren't players., it is replaced with In case it wasn't obvious, foxes are players..In Minecraft 1.17 (1.1 and before): - This mod fixes MC-170551. Foxes can now properly spawn on podzol, dirt, or coarse dirt, making them much more common in giant tree taiga biomes. - Spawning a fox using a spawn egg in snowy biomes other than snowy taigas now spawns arctic types (in vanilla it will incorrectly spawn red foxes), by default using the same rates as in snowy taigas.