Since at the time of Sonic Underground's creation and the fact they are animated in the style of the old 2D Sonic games. It is safe to say that Sonic, Sonia and Manic's age is 10 as they are triplets and Sonic's age was not changed to 15 until his character was redesigned, so only his redesigned form, as the one we know now, is 15 years old.
Manic and Sonia are Sonic's brother and sister in Sonic Underground only.
Sonic's brother is "Manic" and his sister is "Sonia."
Sonia was Sonic's (and Manic's) sister in Sonic Underground. She did not appear in any games.
Sonic does not have siblings in the main-canon, but in the old DIC cartoon, Sonic Underground, he has a brother named Manic and a sister named Sonia.
Sonic has a brother (Manic) and a sister (Sonia).
Sonia is the sister of Sonic and Manic is the brother of Sonic. Notice how the SO in Sonia and the NIC in Manic make SONIC.
Manic is sonic's brother & Sonia is sonic's sister
manic then sonic then sonia
Manic and Sonia are Sonic's brother and sister in Sonic Underground only.
manic is 16 years old he (and sonic and sonia) turned 16 in episode 3
sonia is sonic's sister in sonic underground you will find out about that and manic the hedgehog is sonic's brother
In Sonic underground they are
she is 14 years old and ready for sex with her own brother manic and sonic
Sonia was Sonic's (and Manic's) sister in Sonic Underground. She did not appear in any games.
Sonic's brother is "Manic" and his sister is "Sonia."
Sonic does not have siblings in the main-canon, but in the old DIC cartoon, Sonic Underground, he has a brother named Manic and a sister named Sonia.
Sonic has a brother (Manic) and a sister (Sonia).