There was an art to making snowballs. Centuries of practice had made Jack Frost quite adept at said art, but that didn't mean he stopped practicing. Bunny might have called it slacking off, sitting up in a tree and pressing snow into a perfect sphere, but Jack knew better. It wasn't slacking off, it was warming up (so to speak).
Maybe if he was sitting on the ground, Bunny could've caught a closer look at what Jack was doing and gained a greater appreciation for the workmanship Jack put into his snowballs. Jack didn't like sitting on the ground, though, not any more than Bunny enjoyed clambering up trees. Something about the higher position was just more 'at home' for him. It afforded him a good view of kids enjoying their snow day (another example of his not slacking, Bunny, thank you very much) and made it easier for him to ambush unlucky passerby while making it harder for he himself to be sneaked up on.
When Jack realized that someone was behind him, then, he could be excused for almost falling out of the tree.
He whirled around, grabbing his staff and jumping down from his perch. Raising his staff defensively, Jack turned slowly, feet crunching in the snow as he scanned his surroundings for potential threat. Out of the corner of his eye, he glimpsed a shadow.
"Pitch?"
His hesitant call was answered by a chuckle, followed by a velvety voice.
"I understand we might have similar fashion sense."
Jack felt the chill of metal press hard on his cheek. He glanced down to see a dull gray blade resting against his face. Looking up, he saw someone in a long black robe.
Someone who was not Pitch Black.
A thin white face grinned skeletally down at him. Pale lights shone like fireflies from empty-eyed sockets. Again the specter spoke, her tones tinted with condescension.
"But does the Boogeyman go around swinging a scythe?"
Jack thought back to Pitch's last great hurrah, when the Nightmare King had tried to stab him in the back before getting whipped (literally) by Sandy.
"I mean, sometimes."
The Reaper (because of course it was the Reaper, who else could it be?) frowned, apparently taken aback by Jack's blunt reply. "Oh."
There was an awkward silence. Before Jack could decide whether to break the ice (ha ha) the Reaper beat him to the punch.
"Well, I'm not Pitch," she stated lamely.
Jack nodded. "I kind of guessed."