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