#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