Undertaker's Attributes (formerly FurAttributes) is a simple attribute mod that is meant to be used alongside mods like Passive Skill Trees, without fully committing to mods like Apotheosis which radically change the game. The overall idea here is to give modpack developers access to attributes without the added bloat of the excessive changes added by other mods. Basically, it just makes it easier to balance classes.

Attributes Added and what they do:

LIFE STEAL: Simple lifesteal function. Scales from 0% to 100% (1 to 1 healing).
ARMOR SHRED: Ignores armor, up to 66% at max (won't nulify armor). Scales at a rate of 0.66% every 1 attribute value, to a max of 100 attribute value/66%. Applies to all damage from attackers, NOT other types of damage, like falling, or void.
CRIT CHANCE: A basic crit chance modifier, similar to landing airborne attacks with a sword or axe; basic crits are disabled otherwise. Default 5%, max 100%.
CLEAVE: Melee attacks deal AoE damage in a 3 block radius from the target, up to a max of 50% of the initial damage. Scales 1 to 1; max of 50%/50 attribute value.
CRIT DAMAGE: Increases the damage dealt from critical hits. Default: 25%, max 500%.
DUPLEX: Chance to fire an additional arrow, max of 400 (400% chance to fire 1 arrow = +4 arrows)
PROJ DAMAGE: Increases the damage of ranged attacks (arrows, tridents). Max of 500 (500%). Word of warning: Bows already scale very well with Power Enchants, as Power increases the damage of each arrow by a percentage. Use this attribute sparingly, or Archers will outdps everything.
PROJ SPEED: Increases the velocity of arrows and tridents.
EVASION: Dodge chance, follows this exactly formula: ((evasion * 0.05) / (1+evasion * 0.05) * 0.8).
PASSIVE REGENERATION: Restores percentage of your max HP every 50 ticks. This is very powerful on its own. Default 0 (0%), max 25 (25%). Use this attribute VERY sparingly.
LOOT LUCK: Think of it like Fortune, but as an attribute. Increases the chances of receiving extra drops from mobs, up to 100%. Default 0.
DEBUFF TIME: Modifies the duration of negative effects on the player. Negative values increase duration of Debuffs on player. From -1000 to 100.
BUFF TIME: Like Debuff Time, but for positive effects; increases the effectiveness of buffs from -100% up to 1000%.
SPRINT SPEED: Increases your sprint speed; default attribute value of 25 (+25% speed) and up to a max of 1,000 (10x default sprinting speed).
DAMAGE RESISTANCE: Reduces damage at a rate of 0.66% per 1 attribute point; max 66%/100 attribute value.
HUNGER RESISTANCE: Reduces hunger cost from sprinting and other actions at a rate of 1 to 1, and can completely remove the need for food at absolute max. Default 0, max 100%/100 attribute value.
CRIT RESISTANCE: Basically reduces enemy crit chance against you, particularly smart in PvP. Max of 100 attribute value, though the minimum is hard set to 1.1 damage (a 10% increase).
RUNIC SHIELD: Consumes damage from attacker, creating runic shield around you. After broken - it need 7.5 seconds to start regen again.
MINING SPEED: Self explainatory. From -100% to 200%. Yes, you can slow down mining.
BOW DRAW SPEED: Increase draw speed of any type bows/crossbows. From -50% to 200%.
MANA LEECH: Works only for Ars Noveau and Iron's Spells. 1 attribute = 1% of mana leech from your max mana.
HEAL AMPLIFIER: Increase incoming healing up to 1000%
GLOBAL DAMAGE: Increase any outcoming damage up to 10000%. Calculates BEFORE Damage Resistance.