Create an image of a cosmic octopus swimming through the galaxy, leaving a trail of vibrant street art in its wake, while exploring mysterious underwater wonders hidden within the depths of a black hole.

Visualize a massive octopus with cosmic attributes cruising through the glory of the galaxy. As it navigates the starry expanse, it leaves behind a dazzling trail of street art, vibrant in colors and teeming with vitality. In its adventure, it is also probing the enigmatic underwater wonders concealed within the unfathomable depths of a black hole.