Start the zombie apocalypse use guns to kill the zombies an run away well they will get you eventually
I quite like this idea. Let me just make a few additions and changes.
How about a Zombie Apocalypse Starter Pack?
Zombie Apocalypse Starter Pack - "Ever wanted to call upon the forces of the undead... THEN BEAT THEM TO A PULP? With this pack, you can do just that! Special Item - Get this free 9 mm Pistol to shoot those zombies in the face! (Note: This weapon needs ammunition, dummy!)"
What's in it? Well...
Chalice of the Undead - "This thing is just a stone cup with brains inside! Whose brains? It doesn't really matter." This is like a consumable which when used, will trigger the "RISE OF THE UNDEAD" event in the realm, which will spawn in 10-15 zombies per wave, with a total of 10 waves. If, however, the player dies, the event will stop.
9 mm Pistol - "Use your trusty handgun to fend off those evil zombies! (Note: This gun needs to use ammunition. You better have some one you!") Looks like one of those IRL pistols.
Pistol Rounds x 10 - "Load this into your pistol to start beating those pesky zombies!" Looks like any other bullets. Nothing too special.
All of these will be in the pack, but this would be part of an update which has a few other zombie-related items, which are...
Sawed-Off Shotgun - "Release your inner redneck and fight your undead enemies with this huge gun!" Looks like a shotgun and fires two bullets per round used.
Shotgun Rounds - "Load this into your shotgun to start mashing those annoying zombies!" Looks like your normal shotgun bullets.
Machete - "Don't have ammunition? Don't have guns? Well, you can beat those zombies gladiator-style with your machete!" Looks like a machete IRL.
Hammer/Screwdriver/Wrench/Saw - "Don't know how to use this? Well, maybe you can throw it to some baddies to beat them to a pulp!" These tools are considered as a "gun" when killing zombies. A player can throw them five times before losing them.
Any Zombie Part - "Ew. Why do you even have this with you?" Looks like human parts but with a touch of "Zombie-ness" and "cartoonier". The Zombie Eyeball can also be obtained by combining 10 Zombie Irises and 10 Zombie Pupils. The Zombie Hand can also be obtained by combining 5 Zombie Fingers.
Undead Essence - "The basic essence of the undead squeezed out of them by magic." Looks like Comet Dust in Growtopia, but the color is a mixture of Green and Purple.
Essence of Zombie Willpower - "You extracted a zombie's will to move on right out of them. How cruel." Looks like Comet Dust in Growtopia, but Red.
Reformed Zombie Heart - "It matches the beating of yours!" Looks like a human heart but "cartoonier". Obtained by combining 6 Zombie Hearts, 30 Undead Essence and a Zombie Soul.
Zombie Soul - "It will live on." Looks like a ghost in cartoons. Obtained by combining 15 Undead Essence, 2 Zombie Hearts and 15 Essence of Zombie Willpower.
Overlord Frankenbaby - "Aww, I think it likes you! It will follow you to the ends of all the realms. And probably conquer them with the help of his Undead 'friends'." Looks like a mini Frankenstein's Monster that was fought during the boss fight of the event that will follow the player around. When the player punches, it shoots out purple wind. Obtained by combining 3 Zombie Brains, 4 Zombie Eyeballs, 2 Zombie Hands, 2 Zombie Legs, 3 Reformed Zombie Hearts, 125 Zombie Flesh, 125 Zombie Bones, 163 Undead Essence and 147 Essence of Zombie Willpower.
Features of this update will include:
Zombies:Zombie - Will try to chase the player down and eat them. Drops Zombie Flesh and Zombie Bones in a 1/100 chance. Takes five hits to kill with a gun and 8 hits with a melee weapon.
Speedy Zombie - Zombie which is two times faster than the player. Has a chance to wear a ripped apart The Flash Costume. Drops Zombie Legs in 1/500 chance, Zombie Flesh and Zombie Bones. Takes five hits to kill with a gun and 8 hits with a melee weapon.
Soldier Zombie - Zombie that can shoot it own SHOTGUN which can knock a player out within 10 hits. Has a chance to spawn in wearing a Soldier Helmet. Players who get knocked out stay in their place for 3 seconds. Takes 7 hits to kill with a gun and ten hits with a melee weapon. an Essence of Undead Willpower in 1/9000 chance, Zombie Flesh and Zombie Bones.
Now for the Mini-bosses:
The Undead Handyman- Zombie that throws various tools, occasionally a toolbox, towards the player which can knock them out in 8 hits. Again, players who get knocked out stay in their place for 3 seconds. Spawns holding a random tool. Takes nine hits to kill with a gun and 12 hits with a melee weapon. Drops a Zombie Hand in 1/5000 chance, a Zombie Finger in 1/900 chance, Zombie Flesh, Zombie Bones and a random tool (Hammer, Screwdriver, Wrench or Saw) in a 1/10000 chance.
Ocular Zombie - Zombie that will spawn before the other zombies. Spawns without visible eyeballs, only with two flying eyeballs that surround it and can never hurt the player. Summons a flying eyeball every 5 seconds that chases the players. Takes eleven hits to kill with a gun and 14 hits with a melee weapon but can occasionally dodge the hits. The Eyeballs take three hits to kill with a gun and 6 hits with a melee weapon. The Ocular Zombie drops a Zombie Eye in 1/5000 chance, Zombie Iris in 1/800, a Zombie Pupil in 1/900 chance, Zombie Flesh and Zombie Bones. The Flying Eyeballs drop a Zombie Iris in 1/800 and a Zombie Pupil in 1/900 chance.
The Undead Witch Doctor - Zombie that can summon an army of 3 normal zombies and 5 Flaming Hearts every 20 seconds. Takes 15 hits to kill with a gun and 18 hits to kill with a melee weapon. The Flaming Hearts take 7 hits to kill with a gun and ten hits with a melee weapon and can set players on fire which slow them down. These hearts can also fly. The Undead Witch Doctor drops Undead Essence in 1/3000 chance, Zombie Flesh and Zombie Bones. It can also drop the Undead Staff in a 1/500000 chance. The Flaming Hearts drop a Zombie Heart in 1/6000 chance.
The Boss:
Overlord Frankenstein - This is actually a person wearing something like the Cultist Hood in Growtopia, riding Frankenstein's Monster, or something that looks like it. It spawns during the last wave of the "RISE OF THE UNDEAD" event.
Movement and Attack Pattern - Basically, it moves and attacks just like if you combined every single zombie. It has the abilities of the Speedy Zombie but now with 3 times the speed, Soldier Zombie but can knock them out for 5 seconds, The Undead Handyman but now just like the improved Soldier Zombie, Ocular Zombie but can spawn 3 flying eyeballs and The Undead Witch Doctor but can summon 6 normal zombies and 10 flaming hearts. It just switches between the abilities of the Mini-bosses every minute. The Frankenstein's Monster takes 75 hits to kill with a gun and 95 hits with a melee weapon. When the Frankenstein's Monster is killed, it drops the person riding it and summons 10 Zombies, 5 Speedy Zombies, 5 Soldier Zombies, 3 Undead Handymen, 3 Ocular Zombies and 3 Undead Witch Doctors. The Cultist Person attacks by dropping bottles of scientific solution which slow the player down and occasionally knock them out. It can also strike the player with lightning which paralyzes the player for 15 seconds and summons 20 Zombies. Takes 105 hits to kill with a gun and 125 hits with a melee weapon.
Drops - It drops Zombie Flesh, Zombie Bones, Zombie Legs, Essence of Undead Willpower, Zombie Hand, Zombie Finger, Zombie Eyeball, Zombie Iris, Zombie Pupil, Undead Essence and Zombie Heart in the same chances as the other zombies. It also drops a Zombie Brain in 1/10000 chance.
These were the ideas I thought would be nice to add to your idea.