Plataforms and tiles.

[Baller]

Steam or GOG

Steam

Single Player/Multiplayer

Single

Operating System

Windows 10

Terraria Version

1.4.2.3

Controls Used

Keyboard/Mouse

You can clip through them if the plataforms are hammered and you hold S.

 

[Esther]

this is actually intended, believe it or not. it's called a Hoik.

 

[Baller]

why does it exist

this is actually intended, believe it or not. it's called a Hoik.

just why

 

[Nyenoidz]

Please look through this article on Hoiks (from Terraria Wiki). You may find the answer(s) you seek there.