A character from the Transformers science fiction franchise.
Rumble is an evil Decepticon, a sentient Alien Robot that can transform into a Cassette Tape.
[quote]Motto: "First we crack the shell, then we crack the nuts inside...!!!".[/quote]
Due to errors during the original cartoon's production, there is inconsistency between various media between whether Rumble is depicted as red or blue. The Japanese dub of the cartoon, and thus most Pixiv fanart, depicts Rumble as red.