They level up by how much experience points it has when you level up you need more experience points to level up
However nincada, ninjask, and shedninja, and a bunch of other bug type Pokemon level up the fastest
During your first visit through Chargestone Cave you are gifted with the Lucky Egg this gives the Pokemon holding it x1.5EXP. Another fast way would be to level up by trading over to a different game.
For these you want the Pokemon in the Erratic (22) or Fast (52) groupings. In these I have listed the lowest member of the family.
Erratic: Swablu, Anorith, Bastiodon, Camperl, Lileep, Cranidos, Feebas, Finneon, Nincada, Volbeat, Zangoose.
Fast: Aipom, Alomomola, Audino, Azurill, Chingling, Cinccino, Cleffa, Corsola, Delibird, Duskull, Glameow Happiny, Iggybuff, Ledyba, Lunatone, Luvdisc, Mawille, Misdreavus, Munna, Shuppet, Skitty, Smeagle, Snubbull, Solrock, Spinarak, Spinda, Spoink, Togepi
70 in pokemon black and white
level 49.
You cannot catch a Rhydon in Black and White. You have to catch a Rhyhorn and level it up to level 42. Rhyhorn is only available in Pokemon White in White Forest.
Have a friend with pokemon white 2 host the funfest mission
He does not evolve by level he evolves when u trade to another Pokemon black or white game
I have a stoutland and its my favorite non legendary Pokemon but Reshiram and Zekrom both are the strongest Pokemon on black and white. This is the link to see the srongest and fastest ETC.
Level 5
krookodile evolves at level 40 in Pokemon black and white
Audino doesnt evolve in Pokemon black and white
Throh don't evolve in Pokemon Black and White.
krookdile evolves at level 40 on both Pokemon black and white
The fastest way is to collect every pokeon in dimond /pearl or platinum then transport every last one to black and white then collect every black and white native pokemon
In Pokemon Black AND White, Dewott evolves at level 36. Hope this helps!
70 in pokemon black and white
level 59
Level 54
level 52