A common complaint about some Pokemon , especially in newer Pokemon, is that they are "over-designed" or "look like Digimon". While I prefer more natural-looking Pokemon designs, there are a few Pokemon that I feel have the opposite problem of having designs that are too subtle.
The transition from Remoraid to Octillery has always bothered me. I am aware that the evolution line is supposed to be "hand gun" to "cannon" rather then "fish" to "octopus". Additionally, their move-set (which is full of beam and projectile moves) and Octillery's name show is line's weaponry inspiration. However, if you were look at their designs alone it wouldn't be immediately obvious that Octillery is a cannon; Remoraid's back fins make it look like a revolver, but even this is easy to miss at a first glance.
I think that their designs may have benefited from a few mechanical elements; by either making them cybernetic with metallic and organic parts or completely robotic beings. Mechanical elements would connect the two (a robot fish evolving into a robot octopus makes much more since visually), make their weapon-influence more obvious, and be a good away to highlight the steel type that had been newly introduced in the same generation as these two (though its much to later for that last part now).
I feel that Toucannon has a similar problem. Its evolution family fits together much better than Remoraid to Octillery, but it doesn't show its cannon influence much in its design. Toucannon's name, dex entry, and signature move, Beak Blast, help connect to cannons, but there is very, very, little that shows Toucannon's cannon influence visually (its possible that its beak is supposed to be a heat gauge and that red feather are supposed to look like a lit fuse, but these design elements are so subtle that it almost looks like a normal cartoon toucan.
The most obvious solution would have been to have Toucannon's beak have a cannon-like extension on top of its beak or even as a continuation of its beak. . Its current design makes it hard for me to picture how it even uses Beak Blast. Though its possible that Game Freak didn't do this because it would make it resemble a hornbill rather than a toucan (though considering how the dex calls Sandshrew and Cyndaquil mice despite them looking more like a pangolin and echinda respectively means that Game Freak has never been picky about species.)