Goat Simulator 3

You get the Capybara body from completing the DLC story. Then you have to buy and equip the Speedy Fur for 5,000 currency. You also need to equip the Speedy shoes, which you unlock by collecting a small number of broken relics.

Speedy can be found in Goofville going in a set path. I found it easiest to wait on top on a hill that had a trinket on it that he runs by every 20 seconds. Lick Speedy and the achievement is yours.

You will need three items to get this achievement:

1. "Capybara Goat": Endgame item awarded after finding the Kidney Stone
2. "Speedy Fur": Purchased for 5,000 credits under the Fur option when customizing your goat
3. "Speedy Shoes" obtained after collecting 5 broken relics

Once you have your items, equip the Capybara Goat, Speedy Fur and Speedy Shoes. You will look like this:



Go to Perky Plaza:



Now wait for "Speedy" to race by:



Lick him and achievement unlocked!