Aras Baskauskas Aras Baskauskas

Survivor: Blood vs. Water contestant Aras Baskauskas and his fiancée Christy Petersen welcomed their first child together, the reality star announced Thursday on Instagram.

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"Welcome to the world, River Juozas Baskauskas!" Baskauskas wrote alongside a photo of his son. "May 29th will forever be your day! @crittycat00 and I are so happy to be your parents!"

According to People, baby River weighed 6 lbs, 10 oz. "Christy and I are over the moon at the arrival of our son," he told the magazine. "Neither of us can believe that this little alien is ours, but we are madly in love with him."

Baskauskas won Survivor: Panama and competed with his brother Vytas on Survivor: Blood vs. Water. He moonlights as a musician who goes by the name Odd Us. Baskauskas proposed to Petersen, a model and clothing designer, in November.

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