I have seen a lot of terminal with sweet shape in the beginning of terminal command-prompt, like this:

and i want to add a shape like this :

.....____________________ , ,__
....../ `---___________----_____] - - - - - - - - ¦ ¦¦¦¦D
...../_==o;;;;;;;;_______.:/
.....), ---.(_(__) /
....// (..) ), ----"
...//___//
..//___//
.//___//

i know how to change text color and add a character at the end, but when i add the brev shape it give me an error when i open the terminal :

so how to do this ?