Santa Claus makes his second appearance in the fourth season. His earlier fourth season appearance was in "Halloween v Christmas".
Santa's pet name for the Titans, "garbage children" is said again for the second time in the series. The first time Santa called them that was in "Halloween vs. Christmas". He also likes to switch it up and say "garbage kids."
The Titans (excluding Robin) wear the elf uniforms for the second time in the series. The first time they wore them was in "The True Meaning of Christmas".
Raven is seen unhooded for the 52nd time in the series.
Santa has to use "Christmas magic" (a crowbar) to enter Titans Tower. The reason for this, as Starfire points out, is that Titans Tower doesn't have a chimney. Their chimney exploded in a previous episode, "Birds".
Sticky Joe's favorite brand of canned beans appears to be Baked Banes. The label has a picture of Bane squeezing a bean and saying, "I will bake you!"
When the Titans get in the sled, Raven's eyebrows did not appear
The other Titans making fun of Robin for being Santa Claus.
Santa saying Christmas is over forever.
The Titans getting excited over unusual Christmas gifts such as coal and cans of beans.
Santa and the Titans using "Christmas magic" for the purposes of breaking and entering.
Robin's rapid weight gain causing concern for his health and well being.
The transcript for "Teen Titans Save Christmas" can be found here.
The image gallery for Teen Titans Save Christmas may be viewed here.