A mod that seeks to add vegan alternatives to all Minecraft mob/animal products using the following guidelines:

Nothing added to worldgen
No new crops added

"Veganism is a way of living that seeks to exclude, as far as possible and practicable, all forms of exploitation of, and cruelty to, animals for food, clothing and any other purpose."
- The Vegan Society

What's Included

See the Minecraft Forum thread or the Github README

Recommended Companion Mods

Pam's HarvestCraft - Food mod that adds vegan alternatives for most (if not all) recipes
Not Enough Items - VO integrates with NEI to provide in-game documentation

Goals Before v1.0.0

Balance (I will need a lot of feedback on balance)
Add a Nether Star alternative or an alternative method of obtaining a Nether Star (need ideas)
Add a Dragon Egg alternative or an alternative method of obtaining a Dragon Egg (need ideas)
Make the mod configurable
Add as much cross-mod integration as possible

FAQ

Why?
In-game veganism is simply a playstyle that I prefer, in that I think survival games offer a unique way to explore vegan ethics that the real world doesn't provide. For example, attempting to adhere to veganism within Minecraft leads to weird/interesting questions like, "Is it really self-defense to kill a mob if I'm semi-responsible for mobs being able to spawn at all?". It can also encourage non-standard behavior like building a weapon that does the least amount of damage possible.

Do I have to play as a vegan if I install this?
No, this mod simply aims to allow veganism to be a viable option in Minecraft. If you don't choose to adhere to veganism while using this mod, it'll still do a few nice things for you:

Allows for alternate (hopefully interesting) methods of obtaining mob drops
Gives uses to various vanilla Minecraft blocks/items that didn't really have a use before (ferns, sunflowers, spruce wood, sandstone, etc)

Should I go vegan (in real life)?
Probably.

Screenshots

Various blocks that the mod adds:

The Vegan Option