Don't think a lot of people have lots of experience with that pet...
Also it's not an easy question to answer, as it depends on what the rest of your team is, and why you're wanting to have that pet in your team.
Let's look at the options:
Tranquility vs Survival: I'm not a big fan of Survival, unless maybe on a super fast pet, in which case it will actually buy you a round if you use it well.
Giraffe Calf has 289 speed at 25, which is good but not great.
So for Slot 2, I'd go with Tranquility.
Then Headbutt or Bleat: I really like Headbutt, good damage, plus chance to stun.
Bleat is handy too, as it heals your whole team. The best option here really depends on what you want to do with that pet.
If you want to have it in your team as pure support, using Bleat to heal your team and Tranquility to make it harder/longer to kill, then Bleat is the right choice.
If you want to have it actually deal some damage to the other team, then Headbutt is probably a better choice, otherwise you'll spend most of your time healing and won't do much damage at all.
Hope this helps!