Bah you're right, I ran out of time, though these tips will probably still help in the long term! You'll learn to draw various monster features quickly and possibly start leaning into a certain style.
When it comes to designing, I generally have an core idea then I want to search up reference images to support that. Then I will mentally break down these references images into smaller, possibly usable features that I can add to my monsters.
For example, I was trying to draw a "Hell Guard" which is basically a demon that is strong and heavily armored and is assigned to just guard stuff in Hell. So then I just start looking up demons, minotaurs, demon/hell armor, demon weapons, even just igneous rocks, then I just pick the features I like and try to add them in.
Same applies to this maple story looking Yeti-shroom. I take a core idea "ice mushroom" then think hmm... mushrooms... ice... Oh! Yeti's live in icy areas! Maybe I can mix the features of a yeti onto a maple story looking mushroom?
Then here's a magical clown mushroom
and a killer coconut kinda inspired by the treant from Dragon Quest.
So again, I just take a core prompt idea, find supportive reference images that contain features or elements I think I want to use for my monsters, then finally I just start picking and choosing individual features here and there to add. I hope this helps.