Could this easter egg be against copyright law?

[RainbowPink_2 (Rainbow)]

I added an easter egg a while back, where a little plush of Kirby can be seen under the bed in my game, Ayla.

here’s a better look at lil ol’ Kirby.

But the main question is: should I remove this easter egg? and are easter eggs against copyright law? so far, this is 1 out of 2 easter eggs that reference something outside of Ayla, so far, this is the only one that references something I don’t own.
here’s an IMPORTANT note:
Kirby’s name is not mentioned in any dialog, and this easter egg won’t be seen anywhere apart from under the bed in Ayla’s bedroom.

You can have a peek at the easter egg yourself here.

Ayla (DEMO) - Roblox

[Coldshot_Dev (Coldshot)]

I doubt it will cause any copyright claims as long as you’re not using stolen assets.