All of Bowser's defining characteristics were already present in his baby form, albeit in a much less threatening way. At this young age, Baby Bowser was more of a bratty and spoiled child (arguably more than his future son) than an actual villain and the main motivations behind his actions are either self-preservation or just a general attempt to cause mischief,Also hates yoshi because yoshi wouldn’t give baby Mario to Kamek and Kamek raised baby bowser at the time so baby bowser hated yoshi