Hey Zoobster, the in-battle consumables all have various effects and you can get them from various different sources!
For example, when you defeat a Guard, they will drop the weapon that they are holding and also a Health Kit!
Health kits heal 50% of your max HP!
The Characters at the Zoo also all drop different consumables along with Health Kits! Let me tell you which ones...
Nix, Pepper, Molly and Ollie drop a Box
Larry and Duke drop a Barrel
Bruce and Shelly drop a Shield
Fuzzy and Finn drop a Trap
Have fun, Zoobster! :)