She has dog ears, so it's possible, although most Japanese renditions of Scylla just have her as a straight-up octopus-girl. (Although the original Scylla was supposed to have three dog heads...)
reese said: The three dogs heads are around her waist.
Only in some depictions, in others, she's tentacles on the bottom, and three dogs on top, with no human parts at all.
Even in the dog-torso versions, she's also supposed to be ugly as sin, but when you're making hentai art, you get to take creative license to cute-ify the character.
