From Season 5 (19731974). Since the powers assumed at the Wiki/Fandom don't properly link these two clips, here are their separate pages:
110: https://muppet.fandom.com/wiki/File:R...
101: https://muppet.fandom.com/wiki/File:T...

Some interesting findings:
According to the data currently published in those pages (which is sometimes incorrect), the 110 clip appeared in 44 episodes, having more airtime than the 101 clip that appeared in 32 episodes. They were never both shown in any given episode. Their closest proximity of appearances (one to the other) occurred in Season 20, when 101 appeared in Episode #2515 and 110 appeared in Episode #2517 (with a weekend in between). No information is currently given as to whom is responsible for these clips, but to me, they seem like the work of Jim Henson.

#ClassicSesameStreet #MatryoshkaDolls #nestingdolls