Made with The GIMP
This is the baby form but not pre-evolution of Missingno. (think Manaphy and Phione).
If you know Missingno., then chances are you ran into its cousin, 'M. He would usually be at level 0 but has the same moveset as its counterpart... which lead me to imagine him as a baby Missingno. :'3
But at such a low level, his only use is multiplying your rare candies and masterballs...