My starter is Tepig, and I need a good in-game addition.
I would say that for in-game, Tympole is the best choice as when it evolves it has only one weakness, Grass, which is covered by your Emboar. Seismitoad also learns Surf and Strength, so you don't have to take up team slots with HM users.
Scolipede is not the best choice in my opinion as it shares a Psychic weakness with Emboar.
Source: http://pokemondb.net/pokedex/seismitoad http://pokemondb.net/pokedex/scolipede
