League of Legends (LoL) Question: Build Tank for Wawick

I assume you mean for jungle? Skirmisher's Sabre - Cinderhulk and Titanic Hydra are your core early game, then you can just build defensive items. Spirit Visage and Dead Man's Plate are safe bets, and Thornmail is usually good for late game. Boots are Ninja Tabi or Mercury's Treads depending on the enemy team comp.

I have a guide for Warwick if you need more details, or feel free to ask more questions. ^_^

Assuming you got fed early, on jungle, i'd go for Skirmisher's Sabre - Bloodrazor and Titanic Hydra and tanky boots / Boots of Swiftness for extra mobility, synergy between Titanic and attack speed plus the on-hit effect on your Q.
Assuming you aren't as strong as you should be early, on the other hand, i'd go for Skirmisher's Sabre - Cinderhulk and Titanic Hydra and either Ninja Tabi/ Mercury's Treads.

**Situational items for the last 3 slots would be:
> Iceborn Gauntlet/ Frozen Heart/ Turbo Chemtank: Three great armor+CDR items, great for expanding the potential of most ultimates used in game for most CC/kill potential and E usage during ganks. Iceborn for more damage/stickyness, Frozen Heart for more teamfighting potential and Righteous Glory for more pickoff potential and engaging;
> Spirit Visage/ Adaptive Helm/ Locket of the Iron Solari: Three great mid-late game choices for fighting magic damage and durability in teamfights. Spirit Visage against burst-type mages whose kill potential you can outsustain with your Q and R, Adaptative Helm against venom-type mages like Singed, Cassiopeia, Teemo or even AP Shaco ( Jack In The Box shots), and Solari for added teamfighting/skirmishing potential.
> Zz'Rot Portal/ Sterak's Gage/ Warmog's Armor/ Thornmail: Great late-game items for added tankyness and utility/pressure. Zz'Rot helps keeping sidelanes pushed in so your team can focus on taking objectives and clearing vision/pickoffing, Sterak's Gage adds lots of damage and a shield that can really help while teamfighting (most times it'll be just free AD since it'll pop when you go in a teamfight), Warmog's will give you the potential to go out of teamfights or smirmishes almost dead and come back to tank again for your team and Thornamil should be used most of the times against fed carries whose sustain from lifesteal cannot be matched.