Early Game

In early game, you can choose between going solo or dual lane with another dps or tank. Chew your food talent help you to survive even you are going solo. Harras enemy hero with your slam, heal yourself with devour. Stay near tower, if possible hook the enemy into your tower. With that you can even solo kill if there are no support heroes in same lane on enemy team.

After you have your Tier 2 talent, play more aggresive. Either roam to another lane, or keep pushing lane. With your Tier 2 talent, as long as the enemy is on Vile Gas range you can do dps and keep healed at same time.

Mid Game to End

In mid game to late game, I recommend you to often get natural creep for more exp and easier push. If you can't, keep roaming or help your teammates. Keep doing it until you can get Tier 6 talent. After you get that, now keep sticking with your mates, especially tank. Keep hooking so your team can kill them or atleast make they retreat. Don't go too far, since you are the core of your team.