Place this clip just before the splash in your edit, then follow it with the baby laughing meme for the reaction and layer goofy ahh sounds underneath a second drop if the scene repeats for extra chaos.
About this sound
This is a short voice clip of Peppa Pig saying drop it in the water, lasting under two seconds in her bright, bossy tone. It feels playful and cheekily funny, like a toddler giving a very serious instruction for a silly splash. The line comes from the animated series Peppa Pig.