Before we start going into detail about food chain and webs, there are some key terms your should know
All the conditions that surround a living organism
The place where an organism lives
In this case it was the ice cave.
All the members of a single species that live in a habitat.
In this case it is the minions
All the populations of different organisms that live together in a habitat
In this case it is the yeti and minions sharing the ice cave.
An ecosystem is the interactions of all organism in a specific area, as well as there interactions with non-living (abiotic) things, like water, light, temperature etc.