#1 - bulbasaur

#2 - ivysaur

#3 - venusaur

#4 - charmander

#5 - charmeleon

#6 - charizard

#7 - squirtle

#8 - wartortle

#9 - blastoise

#10 - caterpie

#11 - metapod

#12 - butterfree

#13 - weedle

#14 - kakuna

#15 - beedrill

#16 - pidgey

#17 - pidgeotto

#18 - pidgeot

#19 - rattata

#20 - raticate