The quickest way to shrink in Untitled Gubby Game appears to be buying the size-related packages, then opening your avatar and equipping the gnome legs , gnome arms , and jester torso. A recent forum-style snippet says that combo is what makes your character smaller.

What to try

  1. Buy the shrink/size packages if the game offers them.
  1. Go to your avatar/customization menu.
  1. Equip the gnome legs and arms.
  1. Equip the jester torso too.

Extra note

Another recent result suggests there may also be a size tool in the game, but it does not clearly explain the exact steps in the snippet I found.

Quick tip

If that outfit combo does not work on your server, the game may have changed since the clip was posted, so the size tool or a newer update may be the current method.

Would you like me to turn this into a super-short step list you can paste into chat?