The Water Of Life.

But why? Reviving a pet takes like three minutes

edit: some fair points have been raised below and I think I’ve changed my tune

 

I would like something like that, lately I just buy a new pet and discard the old one

 

Agreed, it may not take long to revive your pet but most of us don't realize the life dried up til we need to use the pet.
Rather than buying a new pet before a party quest, just buy water of life and big, bang boom, done.

 

Specially annoying when your 3 pets die at once and you have to do the "quest" 3 times

 

I think itd be a nice QoL.

Maybe similar to Kenta's advice (quest for pet speed) where if you do it once, you can just double click the water of life to res the pet.