Least favorite recurring Summon designs

[Wolf Kanno]

We talking just a particular summon or an incarnation of one?

Overall recurring, Siren. There's not a single game where I found myself using her, at least Carbuncle is useful in two instances. I think the ones in XII appear in Tactics? If so then almost all of those too because they couldn't take a hit from a small bird.

Incarnation of one. Mostly design-wise but gameplay specs count too if you want to.