Iron Artist 1/100
(Squid Family Robinson)

Cal's parents and sister, whom I decided to develop for some reason! They are the most embarrassing thing in the world to Cal, and he would appreciate it if you would pretend you did not see him here

From left to right:
DaCoda, Lacustris, Cal, and Rika! (Thanks to  Nurio for the name suggestion )
All of them have magical powers, because we all know that mollusks are the source of the arcane. Completely.

DaCoda is (obviously) one fabulous motherfucker, and channels his magical ability through disco music! He is all about partying and having a good time, and is a very good dancer! He's also able to see the future; he makes a living fortunetelling. He's fond of tarot card reading, palmistry, astrology, and similar... His predictions are 100% accurate even without such tools, but he can't really choose what he sees: it merely comes to him. He's a horrible flirt, quite cheesy, but also a load of fun to be around! He's also the shortest, standing at about 5'10" (when not wearing his platform shoes)
[based on the squid species, Abraliopsis morisi]

Lacustris is quite serious and uptight, she channels her magic through classical music. She is a magical and musical prodigy, gifted in many different instruments and schools of magic. She has a stiff personality, but enjoys the finer things in life: good music, good food, and intellectual conversation. Since divorcing her husband DaCoda she's become a lot more stern, but her harshness comes from a good place: she just wants what she thinks is best for her loved ones. She's also a powerful sorceress, and not to be trifled with! (As if you'd really trifle with a 9 foot tall lady with four arms)
[Based on a nautilus of no specific type, considering most of them look so similar]

Cal is the youngest of the family, and channels his magic from swing music! He's incredibly gifted at magic, though is a huge slacker! He has poor common sense and tends to use overcomplicated magical solutions to his problems: creating an impressive trashcan golem to take the trash to the curb, freezing time so he can look for the remote control, or stopping an entire rainstorm just to light a cigarette. For more on him, you can check out this reference sheet thing
[based roughly on a common cuttlefish]

Rika is a fun loving sweetheart, she channels her magic through jazz! She has a sensual way of dressing, speaking, and moving... But in fact is very innocent in personality! She often is sexy on accident, and is totally oblivious in this regard. She is only able to do one kind of magic, and that's shapeshifting! She's able to bend her appearance to impressive lengths: changing color, changing size, changing shape, even creating a doppelganger of herself... Though she can't completely change herself to resemble someone else. She's a great singer and a doting big sister, much to her younger brother's annoyance!
[based on a mimic octopus]

I had a lot of fun with these concepts! Hope they amuse you in some way