Try using a Ditto, if you have one
blastoise
In this case, Blastoise is the best. Charizard has a better advantage against Venusaur because Charizard is a Fire Type and Venusaur is a Grass Type. Still, he has no chance against Blastoise because he is a Fire Type and Blastoise is a Water Type, so overall, Blastoise is the best.
breed it with a ditto or a venusaur of the opposite gender
Pikachu, Lapras, Charizard, Blastoise, Venusaur, Espeon.
Charizard, Blastoise, Venusaur, Lapris, Pikachu, and Snorlax
Pikachu, Espeon, Snorlax, Charizard, Venusaur, Blastoise.
your starter Pokemon can handle it if they are blastoise, charizard or venusaur.
venusaur!?
Pikachu, Charizard, Blastoise, Venusaur, Snorlax, Lapras.
Of course. All it needs to do is have sex (Yummy!) with a female venusaur.
No it cannot.
Manaphy and Blastoise cannot breed. Manaphy can only breed with ditto or another Manaphy.