A majority of the characters in Happy Tree Friends have buckteeth. These are seen most prominently when characters have their mouths closed, though the buckteeth are still visible when they talk, scream, etc. The buckteeth usually cannot be seen when characters grit their teeth or scream with contorted facial expressions. Similarly, when characters grin widely, such the trademark grins of Lifty and Shifty, the buckteeth can become hidden amongst their other teeth.