If voice command "Ho Ho Ho" is used, Run Rudolph Run by Chuck Berry will play inside of the vehicle. If voice command "Ho Ho Ho Not Funny" is used, Grandma Got Run Over by a Reindeer will play inside of the vehicle instead. Otherwise, the two commands activate the same Santa Mode easter egg. While driving or in park, a snow effect appears above the depiction of the vehicle. When parked, the image of the car is replaced by Santa Claus on his sleigh. Using the turn signal will result in the sound of sleigh bells in addition to the normal turn signal sound.

If the "Easter Egg Drawer" is used to activate the effect, tapping the reindeer will result in a message titled "Santa Mode". The message includes instructions on how to activate Santa Mode using the "Ho Ho Ho" voice command. The text box gives an alternative method of activation in the form of button options "Close" and "Ho Ho Ho" appearing at the bottom of the message. No mention of the "Ho Ho Ho Not Funny" variant is made.

In previous versions, the vehicle was depicted as Santa Claus on his sleigh while driving as well as in park. Computer vision would also show the road as ice, and other cars as reindeer while driving.

The songs, either Run Rudolph Run or Grandma Got Run Over by a Reindeer, play for about 1 minute at a relatively high volume. The volume can not be adjusted. The songs can be restarted indefinitely by activating the voice command feature repeatedly. Using the "Ho Ho Ho" voice command a second time will stop the animations, but will not stop the song; rather the song will begin again. However, if the voice command capability is activated after the Easter egg graphic is deactivated, the song will stop. Another more simple way to stop the song from playing at any time is to use the turn signal.

This easter egg works on the Models S, 3, X, and Y

To activate this easter egg: Voice command "Ho Ho Ho" or "Ho Ho Ho Not Funny"