Here’s Dave Cockrum’s original notes and costume drawing for Nightcrawler. Dave had previously come up with the character earlier, and at one point proposed him as a new member of the Legion of Super-Heroes while he was working on that series at DC. As you can see, almost nothing of what Dave proposed as the character’s background remained intact when he became one of the X-Men.
Left to Right. Speckpaw, an obedient and self controlled apprentice with a smile to go around. Brother to Beetlepaw. Dapplejump is a fun and selfless she cat that has perfected her hunting skills and never finishes a patrol empty pawed. Her apprentice is Speckpaw.