Professor Rowan was not released for leaf green.
Prof rowan is only in diamond and pearl and platinum.
just find what you have to do and he will come
you get it from professor rowan after you get the national pokedex
LeafGreen version does not have Growlithe.
In his lab
Dawn is at Lake Verity.
professor rowan doesnt have a lab in eterna but oak stays in a house north west of eterna once u finish the national dex
You get it from the safari warden
Professor Rowan's lab is in Sandgem Town, which is north-east of Twinleaf Town. Hope this helps! :D
You talk to Rowan in his lab then he will give it to you.
A Piplup doll, figure, or card can be found on eBay or amazon; then you can buy it. In a Pokemon game, you can get Pipulp as a starter Pokemon in Pokemon Pearl version , Pokemon Diamond version, or Pokemon Platinum version. The starter Pokemon is the one you get at the beginning of the game from Professor Rowan.
profesor rowan does not hav a dasugher you genius