Shield Master.  The zombie adds +2 to its Dexterity saving throw modifier.  

Multiattack.  The zombie makes two melee attacks.    

Punch. Melee Weapon Attack: +4 to hit, reach 5 ft., 1 target. Hit: 5 (1d6 + 2) bludgeoning damage. 

Shield Rush (1/day). This special ability can only be used once per long rest.  The fast zombie puts up a shield in front of him that blocks all attacks to his front, although he is still vulnerable to attacks to the back.  The shield has 20 HP, and an AC of 15, and it lasts until it's destroyed.  

The fast zombie can ram a player with the shield (+4 to hit, reach 5 ft., one target.  Hit:  (1d4) bludgeoning damage.  Hit or miss, the target must succeed on a DC 11 Strength saving throw or be pushed back 5 ft.  

Charge.  The zombie moves up to half its speed.  If the zombie makes a melee attack immediately after taking this bonus action, before the end of turn, the attack deals an extra (1d8) bludgeoning damage.  

Rage (1/day).  The zombie enters a rage, gaining the following benefits for 1 minute:  

• 1d6 bonus to damage rolls with melee attacks.  
• Bludgeoning, piercing, and slashing damage is reduced by 6 (1d8 + 2).      
• Advantage on all ability checks and saving throws that involve Strength, Dexterity, and Constitution.  
• +10 ft. movement speed.  
• Can take an additional action on its turn.
• Gains 10 temporary hit points. 

Uncanny Dodge (3/day).  When the zombie is hit by a melee weapon attack, it can use its reaction to half the attack's damage against it.