The inflatable dolphin seems useless

[Spagant Floundry]

Most of the projectiles miss every time, and since the projectiles come from the top, they're most likely to hit the pegs you already hit. I'm not sure what about it elevates it to "rare" status, as I haven't found any use out of it any time I've bought it. Buying it often kills my run. Even when triggering it a bunch of times with the void perk, it is easily outperformed by the uranium rod, the power outlet, and the flamethrower.

[Big Joe]

Honestly feel like some items in general need changing in rarity types, some commons are significantly better than some rare and even ultra rares

[GreatSphynx]

dolphin is pretty good if you can get perks that trigger it more frequently, otherwise yeah theres def better choices for the slot