With The Zaishen Menagerie now active, It seems there is a high demand for leveling pets up quickly. In this post I'll describe what seems to be the fastest way to get this done - death leveling with no shrines involved. I've posted a similar explanation on Wiki, I'll elaborate a bit more here.
The key point here is that if character X has 1 hp and then dies, then resurrecting X with a skill that gives less than 50% health will immediately kill X again. Some examples of such skills are Restore Life (with low healing prayers attribute) and resurrect. This makes the following death leveling procedure extremely fast.
Getting 1 hp on a character is easy, simply die (using a sacrifice skill such as Blood is Power) several times while wearing armor with many superior runes. Note that when you have 1/1 hp, you can't kill yourself with a sacrifice skill; in this case, you must switch 1 sup-rune-armor-piece to increase your heath, use BiP twice, re-wear the sup-rune-armor-piece and use BiP again to die.
In order to expedite things, use 2 mesmer heroes with high fast casting (reduces the resurrection skills' cast time by ~50%) and Healer's Boon (another 50% reduction in cast time for restore life). The third hero can be a Well of Power necro to feed energy into the resurrectors. If at the end of the process you wish to be resurrected and not die immediately then at least one hero should have a resurrection skill that gives 50% or more health to use at that time (such as renew life, which should be disabled until then).
More formally, here is the complete build (heroes on avoid combat):
1. Player (you) - [Blood is Power], ([Charm Animal] if you want to cap yourself and if you are a N/R or R/N)
2. Mesmer (Norgu) - [Restore Life], [Resurrect], [Renew Life] (disabled), [Healer's Boon]
3. Mesmer (Gwen) - same as Norgu
4. Necro - [Well of Power], ([Charm Animal] if you don't want or can't cap the pet yourself, this implies being a secondary Ranger)
The Mesmers should have high fast casting and the Necro should have high blood magic, other than that, attributes are meaningless. Both mesmers should each use 1 or 2 "halves spell recharge" modifiers to further expedite the process.
The entire tactic is as follows: get to the pet you want, you can do this inside the menagerie after you have capped a low level pet and released it, or outside, before you cap the pet; I recommend doing it inside the menagerie, a sterile environment where you won't be disturbed. attack the animal once so it becomes hostile (if you do this to a lvl. 5 pet in the menagerie, it won't attack but that's fine, otherwise, it will attack and Well of Power will compensate for this). Station heroes and yourself there. Wear sup-rune-armor and kill yourself using BiP several times until you have 1 HP and are killed immediately upon being resurrected. When the pet is level 20, capture it. If you did this in the menagerie to a level 5 pet, the pet will be hearty as it never attacked and this will unlock all of the evolutions for this pet.
Note that casting restore life will take ~ 1 second, and casting resurrect will take ~ 2.5 seconds. Leveling a pet from level 5 to 15 should take ~ 10 minutes and from level 5 to level 20 should take ~ 20 minutes (assuming the pet doesn't leave your agro bubble which is where it gains XP from your deaths). What's more, you can be AFK while death leveling.
While there are many ways to death level, this is to my knowledge the fastest way to do it.
L


