[Laddybuck]

Minecraft is all about using things for purposes other than their intended one: using cauldrons to power circuits, using pistons as tables, and my personal favorite, populating your town with creatures that want to murder you. Let's face it, endermen have way more charisma than villagers ("Hey. 'Sup?"). Sadly, though claims make the server safer for builds, they also make mob transportation nearly impossible.
To counter this, I'd like to suggest adding hostile mob spawn eggs to the shop alongside the cat and dog varieties. This would consist of adding a selection of spawns at a similar 500 dcd cost, including:
Zombies/Husks
Skeletons/Strays
Creepers
Spiders
Slimes/Cubes
Endermen
Pigmen
Blazes
Ghasts
Vindicators*
Guardians

*I'd like to limit it to common (read: farmable) mobs, but 'Killer Johnny' is rather fun.

Purchasing an egg from the shop would give you one that works eggxactly as they do in vanilla creative: spawns one unnamed mob. What do you think? Would anyone else like to see a feature like this? I'll try to answer any questions and concerns.

[ShadowCrafter]

I like this, it'd be really useful for some builds.

[Brianetta]

It's a nice idea, but it's open to abuse. Hostile mobs are hostile to all players, and some players will harass other players by spawning hostiles around them or in ambush, quite possibly killing them in the process. We can turn off PVP, but we can't choose not to interact with hostile mobs.

[Laddybuck]

That's a fair point, and I have to admit I'm stymied for solutions beyond simply ramping up pricing to make exploitation more difficult, or hoping the folks on the server are more responsible with them.

Edit:
Since the above statement, I've witnessed a system with a similar vulnerability to abuse as mob eggs, that has already been implemented on the server: gadgets, in particular the black hole. It can be used to fling an unsuspecting player off ledges or into a void in ambush, and just like hostile mobs ignores PvP status. It costs many times more than what I proposed an egg would, but can be used infinitely, and though it has the potential to cause harm, I have only seen it used in such a way once on the server, and not maliciously.

Ultimately, I have no say in what is and isn't implemented on the server, but I would like to highlight the existing precedent for somewhat treacherous features being purchasable from the shop.

[clangedinn]

Something like this would defiantly make it easier to make fish tanks and the like and yes some gadgets can defiantly be used to troll,  I personally love using the black hole in the hub for the purpose of throwing folks off a ledge,  i only do this in the hub so i do not end up killing someone due to it.  eggs for mobs would make some builds a little easier.  Though part of the fun of dragging say a guardian to a fish tank is trying to do it without dying.  I have not had to deal with claims affecting anything like that but if they do i can see this being a pain in the neck.

[Attila]

It's a nice idea, but it's open to abuse. Hostile mobs are hostile to all players, and some players will harass other players by spawning hostiles around them or in ambush, quite possibly killing them in the process. We can turn off PVP, but we can't choose not to interact with hostile mobs.

In most cases I would love for these items to be in shop, however, as Brianetta brings up the "abuse" with most mobs, it would just cause too much harm to anyone on the server.

Plus, Rendog has made this as a survival world, so if you really want to mess with people with zombies (or other mobs), just run around at night and let them chase you and bring them to other people ( I know this is a **** move, but if you want to mess with others, at least work for it).

...eggs for mobs would make some builds a little easier. 

Just work your butt off at getting the mobs, again putting the emphasis on being a vanilla SMP, things are meant to be difficult if you want to achieve a goal.

[_edo]

Just work your butt off at getting the mobs, again putting the emphasis on being a vanilla SMP, things are meant to be difficult if you want to achieve a goal.

Can't agree with this statement more.
If a mob can be acquired in a vanilla way, I don't see any need to have it in the shop as a spawn egg.