Teenage Mutant Ninja Turtles: The Complete Classic Series Collection
In Leonardo's nightmare, Raphael refers to Rocksteady as "hog-breath" which is the common insult for Bebop.
When the Turtles slide on the ice while running from the polar bear, Leonardo can be heard screaming as well, and the same would happen when Donatello slips on the snowy stairs and crashes on Raphael and Michelangelo, but Leonardo isn't in either of these scenes.
After Donatello falls down the snowy stairs in the schoolhouse, the Turtles (except Leonardo) gain snow boots.
When Leonardo leaves the Turtles, he wears his winter disguise, but when returning, he wears his blue colors, and the snow boots the others got suddenly in the snowy schoolhouse.
During Leonardo's nightmare, a dog clearly bites Leonardo's foot, but he shows no response.
Leonardo was seen with no swords in his hands in the close-up shot of him charging towards Bebop and Rocksteady but the swords appeared when he knocked the pair when they turned into giant punch bags in his dream.
Shredder's skin is almost orange in this episode and the lenses on Bebop's shades are coloured purple.