Alpha Child Space: 1999 : Season 1 Episode 7

The Alphans celebrate the arrival of the first child born on the Moon. The blessed event sours when the infant grows into a five-year-old child in minutes. Trying to accept him, the Alphans do not notice that little Jackie Crawford is much more than he seems. When hostile spaceships approach the base, Koenig realises, too late, that the aliens have an agent on Alpha.