(Or "character graphics", "ASCII graphics") The fine art of drawing diagrams using the ASCII character set (mainly "|-/\+").

See also boxology. Here is a serious example:

   o----)||(--+--|<----+   +---------o + D O
     L  )||(  |        |   |             C U
   A I  )||(  +-->|-+  |   +-\/\/-+--o -   T
   C N  )||(        |  |   |      |        P
     E  )||(  +-->|-+--)---+--)|--+-o      U
        )||(  |        |          | GND    T
   o----)||(--+--|<----+----------+
   A power supply consisting of a full wave rectifier
   circuit feeding a capacitor input filter circuit
                         Figure 1.

And here are some very silly examples:

|\/\/\/| ____/| ___ |\_/| ___

| | \ o.O| ACK! / \_ |` '| _/ \

| | =(_)= THPHTH! / \/ \/ \

| (o)(o) U / \

C _) (__) \/\/\/\ _____ /\/\/\/

| ,___| (oo) \/ \/

| / \/-------\ U (__)

/____\ || | \ /---V `v'- oo )

/ \ ||---W|| * * |--| || |`. |_/\

                //-o-\\
         ____---=======---____
     ====___\   /.. ..\   /___====      Klingons rule OK!
   //        ---\__O__/---        \\
   \_\                           /_/
                                    _____
                            __...---'-----`---...__
                       _===============================
  ,----------------._/'      `---..._______...---'
  (_______________||_) . .  ,--'
      /    /.---'         `/
     '--------_- - - - - _/
               `--------'
                           Figure 2.

There is an important subgenre of ASCII art that puns on the standard character names in the fashion of a rebus.

+--------------------------------------------------------+

| ^^^^^^^^^^^^ |

| ^^^^^^^^^^^ ^^^^^^^^^ |

| ^^^^^^^^^^^^^ ^^^^^^^^^^^^^ |

| ^^^^^^^ B ^^^^^^^^^ |

| ^^^^^^^^^ ^^^ ^^^^^^^^^^^^^^ |

+--------------------------------------------------------+

             "A Bee in the Carrot Patch"
                       Figure 3.

Within humorous ASCII art, there is, for some reason, an entire flourishing subgenre of pictures of silly cows. One is shown in Figure 2; here are three more:

          (__)              (__)              (__)
          (\/)              ($$)              (**)
   /-------\/        /-------\/        /-------\/
  / | 666 ||        / |=====||        / |     ||
 *  ||----||       *  ||----||       *  ||----||
    ~~    ~~          ~~    ~~          ~~    ~~
  Satanic cow    This cow is a Yuppie   Cow in love
                          Figure 4.