Roy comes to mind, and to add more salt to the wound, he was considered for Brawl like Mewtwo and still didn't get one.
Brawl's trophies reused models from existing non-Smash games if the models weren't made for Brawl itself.
Roy didn't have any model outside of Melee, same with Dr. Mario (until Dr. Mario Online Rx, which came out
after) who was
also planned for Brawl and didn't make it.
Paula and Poo don't have trophies, but Jeff has one (well, maybe this is because he is an AT).
Jeff was an AT and Paula and Poo did not have models from their game to use.
The Striker Daisy trophy instead of a normal Daisy trophy.
A better example, but not quite the same as Diddy completely lacking a trophy in Melee while K. Rool and
Dixie had one and my previous examples of Anthony and Waddle Dee.
The Striker Daisy trophy is treated as Daisy's trophy in general, just like her Tennis and Baseball trophies in 3DS and Wii U, respectively.
The Falco (Command) trophy inclusion, but the lack of, for example, Fox (Command).
Honestly, the trophies
themselves don't really make sense other than for filler purposes considering they're extraneous trophies for characters that have trophies already. Wolf not having an Assault trophy and Fox, Wolf, and every other Star Fox character other than Falco not having a Command trophy doesn't really come up as an issue.
The inclusion of the Baby Mario and Baby Peach trophies with the lack of Baby Luigi trophy.
Probably the strongest example here, though it can probably be explained by Baby Peach being one of the babies that can ride Yoshi in Yoshi's Island DS while Baby Luigi
isn't, since the Yoshi trophies are limited to just Yoshi, his Final Smash, Baby Mario, and Baby Peach in Brawl and focus on the Yoshi sub-series as opposed to appearances outside it.
It could be argued that since Baby Luigi is typically the one who needs rescuing that he should've got a trophy, though. *shrugs*
Tiny and Lanky trophies, but no Chunky trophy.
Tiny and Lanky have models from Barrel Blast to use. Chunky does not.