Unicron's manifestations

Unicron created manifestations of himself to destroy the Autobots.

"One Shall Rise, Part 1"
Near the end of the episode, Unicron created one big manifestation of himself to fight Optimus Prime. Optimus blasted the big one but dozens of manifestations showed up and surrounded Optimus.

"One Shall Rise, Part 2"
Optimus destroyed several of the manifestations, but they were able to overpower him. However, Team Prime showed up and aided Optimus in battle. They blasted manifestations and tried to escape them, but they faced a gigantic manifestation. This one was hard for the team to destroy and it easily overpowered them. It was close to killing Optimus until Megatron saved Optimus by blasting the manifestation. Megatron fought the other big manifestations while the team retreats back to base.

"One Shall Rise, Part 3"
The manifestations were destroyed when Optimus Prime used the matrix on Unicron's spark.