Lip syncing

“I like lettuce” - https://m.youtube.com/watch?v=c9e4SBL-v14

“To infinity and beyond” - https://m.youtube.com/watch?v=IDU-36-IEoA

“Hello there” - https://m.youtube.com/watch?v=su6OHouCU7s

“I’m sick of falling down the stairs” - https://m.youtube.com/watch?v=Xu1ISwJt2mk

“I want some big boi chicken nuggs” - https://m.youtube.com/watch?v=nAHxgzgS-o0

Lip syncing is making a animated character give the impression of speaking. This is done by using different still mouth images  across the frames.