Alistar jungle is a good replacement for those who go damage support (Ex: Annie), but can still go jungle at any time. The purpose of this build is to help your team survive with the Health bonus, Armor bonus and Magic Resist bonus from Windspeaker's Blessing that supports your allies during a team-fight while also being able to play on the offensive with the On-hit damage and Attack Speed bonus from Ardent Censer.

Pros

+ Provides a support role in the jungle + Godlike ganks + Protects Carries + Provides Damage and Health for the team + Provides Armor and Magic Resist + Extremely tanky

Cons

+ If your team does not team fight, Alistar's use in the team becomes minimal + High Cooldowns early on + High Mana Cost (fixed with mana regen and mana items) + Low movement speed + Useful CC + Very slow clear speeds

Core Items:

Skirmisher's Sabre: Allows you to counter those pesky rengars and lee sins that try to counter jungle you, also pretty useful for just dealing extra damage in ganks.

Ninja Tabi: Block all the auto-attacks.

Ardent Censer: Gives your team Attack Speed and On-hit damage with your AOE heal. Helps all of your abilities with the Mana Regen, Cooldown Reduction, Movement Speed, and Ability Power (somewhat) that this item provides. It's also pretty good when you get objectives with your team.

Late Game Items:

Spirit Visage: MR, Health, Cooldown Reduction, and a bonus to your own healing.

Iceborn Gauntlet: Large amount of armor, 20% Cooldown reduction, Mana for your abilites, and a bonus spellblade effect.

Dead man's Plate: I get this for the movement speed and the passive, if you would prefer Randuin's Omen you can easily swap it out.

Situational Items:

Frozen Heart: Same thing as iceborn gauntlet but can slow attack speed and gives more armor without the sheen proc.

Randuin's Omen: Excellent replacement for Deadman's. Can be switched out for this if you really want to have it.

Thornmail: this is not the best item for Alistar because of his ult, but can be switched in if you are against an AD team.

Locket: this item makes you a true jungle support, I really want to put this in the build but i can't see it being place anywhere unless you switch iceborn out for frozen and replace deadman's with locket.

ROA: Mana and Health with AP.

Banner of Command: same situation with locket but less supportive utilities.

Rylai's Crystal Scepter: Annoying for the enemy because they are slowed after a slam and/or headbutt.

Athene's Unholy Grail: cdr, magic resist, mana regen, all things essential to Alistar.

Hello, My name is SefusJack and I'm not a professional leaguer. I am only a plat 5 and I'm also not the best Alistar. I just happen to have a hobby of making builds in my free time and I wanted to share it. Any questions, please comment if you believe something is wrong.