Lord Monochromicorn

Lord Monochromicorn is the gender-swapped version of Lady Rainicorn, created by the original series designer, Natasha Allegri and featured in "Adventure Time with Fionna & Cake." He is completely black with a long, gray mane (appearing pink in this picture due to lighting), entirely different from Lady Rainicorn's multicolor scheme. His name also indicates this, with "mono", meaning "one", and "chromo", meaning "color". Also, his appearance is more horse-like compared to Lady Rainicorn. He is the loyal companion of Prince Gumball, who is Princess Bubblegum's gender-swapped version. He communicates by using his hoof like a telegraph to communicate with Morse Code, rather than by speaking Korean, as Lady Rainicorn does. (he stomps his hoof for a dot and scratches the floor like a line for a dash) According to Natasha Allegri, he can open up black holes, like how Lady Rainicorn can turn things into rainbow colors He is also the boyfriend of Cake, just as Lady Rainicorn is the girlfriend of Jake.

Trivia

 * Lord Monochromicorn can neigh.
 * During his first appearance in the actual show when Cake asks him "How're you, gorgeous?" he replies "Hey" in morse code.
 * When Lord Monochromicorn made his first appearance on screen, the sound of thunder could be heard in the background. This was probably done to tie him in with Storm Clouds, like Lady Raincorn. Like how she is associated with Rain, and the rainbows they make when the sun shines on them at the right angle, Monochromicorn is associated with the storm clouds that create the rain.