We have elephants on the list, but also magma rhinos.
"Pull the lever" on the switches, and the fact that the traps are currently lava-based, are another reference.
This game is so different from DF that we feel pretty free with the ability to put in a lot of homages to it; we're in no way competing with their market. I just really love build in homages to games I like and respect in all my games, but I'm always careful not to do it to a game or genre that is too close to the game we're actually making.