The "savage" warrior with an animal companion is a staple of pulp fantasy/swords & sorcery. However, if you wanted to play a warrior with a tiger for an animal companion, you're looking at a 7th level Druid or 14th level Ranger according to the SRD.
Is there another way to represent this classic fantasy archetype using another class, feats, spells, magic items or some use of the Handle Animal skill? I'd like to play this character starting from 1st level, if possible, or at least not require a minimum of 7 levels.
Also, Druids don't seem like a good fit for this barbarian-type, although maybe re-skinning the semi-celtic flavor of the SRD Druid as something more tropical could work.
I'm open to any combination of the above + creative uses of in-game fiction as well (ie whistling for his tiger friend == casting summon animal, etc).
Best Answer
If using Pathfinder, you can use the Summoner class from the Advanced Player's Guide. Though it's a caster class, it's got d8 hp, and can do "no armor, spear, knife" just fine. Have your eidolon (powerful pet) be a tiger, and then your other Summon Monster uses can be Tarzan-like bellowing to the jungle. Works from level 1 and scales. This means the tiger will take the lions' share (liger's share?) of your combat activity.
As a druid, you could just have an animal that uses the Cat, Small stats until 4th level and then grows into the Cat, Large stats - just instead of swapping out companions, say it's the same one. Ta da.
Take an appropriate class template like the Jungle druid, or Beastmaster ranger, and then take the Boon Companion feat which ups your effective level by 4 for animal companion purposes.