Off-ball: Seed Plant
Plant the seed of a bush, denoted with a small bump and sprout coming out of the ground. Provides a small vertical boost, close in height to a standard jump, and can be done midair with the seed simply falling straight down. This isn't accurate to anything the beetle does, but it works around the on ball.
On-ball: Bury
Bury a dung ball where you are. If there is no seed nearby, it will come back out of the ground after a few seconds one stage smaller. If there is a seed nearby, it grows it into a bush scaling to the size of the ball. The bush slows down enemies inside of it and balls cannot pass through, not affecting teammates.
Passive: Khepri's Blessing
As a reference to how scarabs are related to the the sun god Khepri in ancient egyptian mythology and was thought to roll the sun across the sky, the beetle acts differently with a golden ball. You gain movement speed and jump height, and your on-ball launches you in a large arc instead of burying the ball.