Complex sentence: Brambleberry of RiverClan has more than once been able to warn humans of danger by hearing and flehming, and she was the first to discover the truth about AntiVandalBot when he posed as Cluebot and quickly became friends with Thekillerpenguin to weed him out.
Split into simpler sentences: Brambleberry of RiverClan has more than once been able to warn humans of danger by hearing and flehming. She was the first to discover the truth about AntiVandalBot when he posed as Cluebot and quickly became friends with Thekillerpenguin to weed him out.