Shadow is the 1st Ultimate Life Form. He is known as Project: Shadow.
Family
- Gemidi the Hedgehog (Mother, deceased)
- Black Doom (Father, deceased)
- Emma the Hedgehog (Sister, deceased)
Friends
- Lizzy the Hedgehog (Cousin)
- Abby the Hedgehog (Secret Crush)
- Cammie Stewart
- Sammy Nooken
- Rocky the Rat
- Kark
- Ramona Lovely
- Mimi Lovely
- Rouge the Bat
- E-123 Omega
- Grace the Hedgehog (Half-Sister)
- Jenna the Hedgehog (Half-Sister, deceased)
- Maria Robotnik (Best Friend until death)
Rivals
- Sonic the Hedgehog
- Klonoa the Hedgehog
- Tabitha the Cat
Enemies
- G.U.N. (For killing Maria)
- Dr. Eggman
- Metal Sonic
- Black Doom
- Solaris
- Mephiles the Dark
- Bailey the Dark Wizard
- Ricther
- Henry (For killing Ramona)
- Arjar
- Elishia (For kidnapping and hurting Mimi, but forgives her)
- Avalon the New Night Master
Love Interests
- Abby the Hedgehog (Love Interest, then Enemy, then Friend, then Secret Crush, then First Kissed, then Girlfriend, then Wife)
- Courtney the Hedgehog (Friends with Benefits)
- Ramona Lovely (Friends with Benefits, deceased)
- Kristen the Hedgehog (Ex-Girlfriend)
- Rouge the Bat (Being Flirted)