I was just thinking during the post-kickoff strategy discussion about how robots don’t have to have wheels.
Does anyone know of a team that made a robot that could crawl like a crab or a dog and used it at a competition? It would be really cool but super hard to program.
Yes, in 2013 teams started touching the pyramid and got points for being above certain levels at the end of the game. There were teams that just climbed the pyramid.
Also, (and more to your point) in 2003 team 71 used nail files as feet and crawled along the field.
We did have wheels, though the goal was to not have to use them. 
TEAM 276 - The Madcows from Youngstown, Ohio used a walker - like module on both sides of their robot from 2003 - 2008.
Yep, we technically had wheels, but here’s our 2013 bot. (warning: very bad noises)
Tank treads were popular in the early days of FRC and a smattering of teams have continued to use them occasionally.
In 2001, team 25 vaulted over a 12" bar.