If you didn't choose it as a starter, you cannot get Piplup throughout the game at all, unless you have cheats/a hacked game, or you get a friend to trade one to you.
You cannot catch Piplup in any game.
Piplup
Turtwig, Chimchar, and Piplup.
Chimchar, piplup, and turtwig.
Get a piplup as your starter. It can beat the 1st gym really easily. Capture a starly and train it so it can beat the 2nd gym.
you get piplup as a starter in Pokemon diamond/pearl/platinum
turtwig,chimchar,and piplup
Piplup,Chimchar,Turtwig
turtwig chimchar piplup
pick it as your starter
Usually at target you can find a piplup doll in the Pokemon section. If you are asking 'Where can you find a Piplup in the Pokemon game?' you need the ds games Pokemon Diamond, Pokemon Pearl, or Platinum.
in the begining of the game If you want a piplup and a turtwig or chimchar I suggest trading.