There's a whole range of non-toy Transformers Prime merchandise popping up at retail at the moment - a large chunk of it in the form of bathtime sets! 2005 Boards member moreprimeland reports that among the other items released, there is a Soak and Slam set of Transformers-themed shower, bodywash and suction cup basketball (Spike, compute quickly!). There's also a Great Smile set of toothbrush, holder and cup, plus a Transformers Prime bubblebath set. At $10 this one includes Optimus Prime, Bumblebee and Megatron bubblebaths - the Optimus Prime one has also been found sold individually for $2.99 by 2005 Boards member Shark Jumper.
Last but by no means least there's also an Optimus Prime plush pillow - a pillow done in the style of Optimus' truck mode. That one is reportedly going for $20 at Target.