Summon Random Vanity Pet Macro

Description:
This will first attempt to dismiss any vanity pet you have summoned, and then attempt to randomly summon a new one.
Macro:

/run DismissCompanion("CRITTER"); CallCompanion("CRITTER", random(GetNumCompanions("CRITTER")));

Description:
This is a more advanced version of the above macro, as it first attempts to determine whether or not you already have a pet summoned. If not, it summons one, else it dismisses it.
Macro:

/run local z;for i=GetNumCompanions("CRITTER"),1,-1 do local _,_,_,_,s = GetCompanionInfo("CRITTER",i); if s==1 then z=1;end end if (z==nil) then CallCompanion("CRITTER", random(GetNumCompanions("CRITTER"))) else DismissCompanion("CRITTER") end