While I Was Playing The Latest Version (1.14) I Found A Glitch With Fences I 

Broke It By Accident And Replaced It But The Pig Ran Into The Fence

And When I Placed It There Was A Weird Shape Hopefully You Saw It In

The Pictures.

How To Create This Glitch:

1- Get A Small Hitbox Animal (Won't Work With Baby Animals)

Ex: Pig, Chicken (those i tried and worked)

2- Create A Fence Around It

Ex: 6x5, 5x9, etc...

3- Break One Fence

4- Hit It One Time 

5- Once It Runs To Get Away Place A Fence Quickly

6- Viola!!! You Got This Weird Glitch

P.S. This Is My First Report So If It Is Not Organized Forgive Me.