A family birthday celebration descended into festive chaos when a costumed Grinch burst onto the scene, sending children screaming and adults scrambling. The clip, posted by @undertheinfluencers_, has now reached 532,000 views.

The family said only two people were in on the prank: the filmer and her sister, who secretly dressed as the green Grinch character before banging on the windows just as everyone gathered to sing happy birthday. The surprise instantly threw the room into holiday‑themed pandemonium.

The filmer’s dad, holding a six‑month‑old baby, can be heard urgently saying “Hold the baby, hold the baby” as he tries to pull the door shut, while her four‑year‑old son raises his fists in full defence mode — especially once he realises the Grinch is stealing Fred, the family’s Elf on the Shelf.

Kids scream, babies cry, adults scatter, and the Grinch’s dramatic entrance turns into a scene of pure family chaos, much to the delight of viewers. The filmer said she has watched it “a million times” and it “never gets old.”

My extended family was spending the weekend in the Poconos and we thought it would be funny to have my sister dress up as the Grinch. We were the only two that knew about it which made the reactions even more chaotic. We gathered all the kids around to sing happy birthday to my nephew and my sister snuck out to get dressed in the Grinch costume. Just as we were ready to sing, she started banging on the windows from outside. My dad, who was holding my 6 month old daughter, tried to fend "him" off by pulling the door closed. You can hear him telling my cousin "Hold the baby, hold the baby" like he was ready to fight! My son who was 4 at the time has his little fists held up and completely loses it when he realizes that the Grinch is stealing Fred, our Elf on the Shelf. All the while kids are screaming, babies are crying, everyone is running in different directions. I have watched it myself a million times and it literally never gets old.