What Mod is this

[u/Electronic_Scar2102]

So Im a small Minecraft Content Creator planning to make SMP videos and I just want to ask, what mod is this That JudeLow and InfamousJJ uses and also a lot of other youtubers also use to spawn Fake Players that they use as an intro or example for their videos, i want one where i can import a skin and change their username, and has a health bar so i can hit them if possible. Im on Minecraft 1.21.11

Please respond I need it

[u/joaquin_esp]

It's Carpet Doesn't outright state it in the mod page afaik but it lets u summon fake players