Why does Assistant Guard feel more expensive than Oozeling Gladiator?

It just struck me - I was desperate to find exactly one Taunt, to protect against cleave or Bramble, but I passed up on Assistant Guard, only to happily take Oozeling two rolls later. So.. why does Assistant Guard cost 7 mana?

Jokes aside, I really felt like that for some reason, Oozeling was a better deal. Subconsciously. Must be the smile and joy you get for free with Oozeling.