Title. Chroma Whelp, Love puppy, and of course the mewkat ARE cute, but from what I saw in the clockworks today, there could be more babies in the monster pocket club.
By that I mean:

Baby (tier 1) Voltail
Additional notes: You can't say a tier 1 voltail isn't cute Its more cute than a wolver! The baby might in fact be cuter than normal.

Baby Snipe
Additional notes: Okay, I have no idea how Nonna would get those, but who wouldn't want a baby snipe pocket?

Baby Yesman(Green Devilite)
Additional notes: Okay, I can't think of a reason why a Yesman is cute, but it simply is cute.

Baby Sprite
Additional notes: Every time I do FSC with someone for the first time, I hear stuff like "Man, the sprites are cute." I agree.

Baby Lost Soul (The vial vendors in moorcroft and npcs in FSC:Blackstone Bridge)
Additional notes: Okay, this creature isn't cute. But it would be fun to have one in your pocket ;)

Baby Gremlin
Additional Notes: I have no idea why Nonna would randomly sell her specimen's children, but still. Cute.

Green/Ice/Pink/Brute Jelly Mini
Additional Notes: The Jelly Mini's are useless, by that I mean, their drops. Nothing. So, how about Nonna randomly picking them up thinking there children slimes? PS: The brute jelly is the blue one, ever saw a Geo Knight who had one as a pet?

Baby Polyp
Additional notes: suggested by Grittle

Mini Lumber
Additional notes: Suggested by Grittle

Baby Sloom
Additional notes: Suggested by Grittle

Baby Sloombargo
Additional notes: Suggested by me in response to Grittle

So, which babies did I miss?