Here is how this works. Someone chooses a random pokemon like Gliscor and then you write a pokemon for each letter of that name and the last pokemon is the one for the Next poster. I'll start:
Gliscor
G: Goudron
L: Lopunny
I: Ivysaur
S: Shuckle
C: Crawdaunt
O: Octillaty
R: Regirock
Now the next poster has to spell the last pokemon in the word, using each letter as a pokemon name, which in this case will be Regirock.
Gliscor
G: Goudron
L: Lopunny
I: Ivysaur
S: Shuckle
C: Crawdaunt
O: Octillaty
R: Regirock
Now the next poster has to spell the last pokemon in the word, using each letter as a pokemon name, which in this case will be Regirock.