Wasn't there some weird alien thing with a massive head? That one.
As stupid as Cyroganal is, I find it pretty memorable... if only because of how awful the design is. Ditto for the ice cream cones.
Alomomalomalomola is pretty forgettable as well. It might have a bit more going for it if it could be found somewhere, or if it was Luvdisc's evolution.
The tadpole thingy?
As a early game useless peripheral, Purrloin is at best unremarkable, and at worst absolutely non-existent.
Escavalier is pretty awesome, but I can't remember the pre-evolution's name or even what it looks like. I know it doesn't resemble a snail in the slightest though.