>>43200176General rule is
>BabyLiteral circle/blob, oftentimes with eyes only. Doesn't necessarily resemble its future evos.
>In-trainingStill very simplistic in shape, most have short limbs and a full face already, and just like baby, they don't necessarily share colors or shapes to what will be their base form (Tsunomon>Gabumon).
>RookieNow this is the base monster, so to say. Some are as small as Patamon or Salamon, the standard are more like Agumon, Gabumon, and then some are quite big like Renamon are Guilmon. Going for a first or second stage Pokemon here is your best bet.
>ChampionThis stage is fairly consistent, and Digimon's wackyness oftentimes doesn't set in here (doesn't mean it can't happen because it can). Dinos become bigger dinos, foxes become bigger foxes, etc. As long as it fits thematically you'll be good for the most part.
>UltimateNow this is where it gets funky. Some lines do still follow the "it just gets bigger" (Greymon>Metalgreymon), some are quite different but keep their theme (Birdramon>Garudamon), and some are completely different (Gatomon>Angewomon). This stage is entirely up to you and what you want to do with it. Anything is fair game, but forrrr the most part color consistency between stages is still kinda kept.
>MegaIn most cases, megas are a sort of culmination of the entire line. 50% tend to be fairly humanoid, and most gain an armor of sort, be it in mecha form, a literal knight armor, some sort of protection, you get it. The other 50% goes full on mythical beast, with very complex designs. It's the smartest and most powerful form (and imo the most aesthetically pleasing).
As a reminder, some lines don't follow anything I just said at all, Digimon can get very weird and "I do whatever the fuck I want". Some lines may all follow a pattern/theme very strictly from start to finish (Renamon line) and others just.. go from cat to dog to cat to angel to dragon (Salamon line). These are just very basic and broad guidelines.
