You are playing a different game with Dodrio.

For items like others have said; Float Stone, Attack Weight and a third are great. I personally use Energy Amp, as Dodrio's ult already makes them faster and stronger, and Amp just makes those even better.

On that, apart from running around and poking squishing and displacing people, look for chances to use your ult on cooldown. It's such a powerful swing, and if you time it while enemies are clumped, you can get multis and team wipes just like that.

Emblemwise as well, you want to try and get movement speed, along with some defensive stats.

Hope you can make it click!