Kon

Kon is a Modified Soul, one of a batch built during Project Spearhead to be dropped into corpses and used against Hollows. Soul Society cancelled the programme and ordered every unit destroyed, and Kon survived the purge by being sold off as a Soul Candy pill. That is how he ends up in Ichigo Kurosaki's hands: swallow the pill, the Shinigami leaves the body, and Kon takes the wheel.

His model is an Underpod, which means the enhancement went into his legs. He can clear a rooftop in one jump and land a kick hard enough to matter, which is the only reason a stuffed lion is ever the most dangerous thing in a scene. Most of the time he is exactly that, a plush toy carried around in Rukia Kuchiki's backpack or thrown across a room by Ichigo's sisters, complaining the whole way.

The joke works because the character underneath it is not one. Kon was made to be used and discarded, and he knows it, which is why he reacts so badly to watching schoolboys delete game characters they had built. He guards Ichigo's body while Ichigo is out fighting, keeps the family from noticing anything is wrong, and takes the beatings that come with both jobs. When the series needs someone to say the thing nobody else will, it is usually the lion.