Amumu's autoattacks reduce the target's magic resistance by 15 / 20 / 25 for 3 seconds. The debuff doesn't stack but it refreshes with every autoattack.
Bandage Toss
Range: 1100
Cooldown: 16 / 14 / 12 / 10 / 8
Cost: 80 / 90 / 100 / 110 / 120 Mana
Active: Amumu tosses a sticky bandage in a straight line towards a target location. If it contacts an enemy, Amumu will pull himself to it, dealing magic damage and stunning the target for 1 second.
Toggle: While toggled on, Amumu will be surrounded by a small damaging area of tears. Enemies in the area will be dealt a percentage of their maximum health plus a base amount as magic damage each second.
Base Magic Damage: 8 / 12 / 16 / 20 / 24
Max Health to Damage Ratio: 1.5% / 1.8% / 2.1% / 2.4% / 2.7% (+ 1% per 100 AP)
Tantrum
Range: 200
Cooldown: 10 / 9 / 8 / 7 / 6
Cost: 35 Mana
Passive: Amumu takes reduced physical damage from autoattacks and abilities.
Physical Damage Reduction: 2 / 4 / 6 / 8 / 10
Active: Amumu will make an instantaneous tantrum, dealing magic damage to surrounding units. Additionally, each time Amumu is hit by an autoattack the cooldown on Tantrum's active will be reduced by 0.5 seconds.
1350 or 
585
