The Hanonian land eel was the first alien being on Star Trek: Voyager (1995) created through CGI. They would experiment with the technique again in Macrocosm (1996) before using it to create Species 8472 for Scorpion (1997).
The Doctor continues the ongoing Star Trek joke of "I'm a doctor..." with the response of "...not a counter-insurgent".
Suder asks the Doctor if he has a portable thoron generator because thoron particles neutralize tricorders. The Doctor replies that he does because they use it to treat radiation burns. Ironically thoron is a highly radioactive isotope of radon, it is an alpha decay particle and a highly toxic form of ionizing radiation that can cause lung cancer when inhaled as a gas, even in small quantities. However as an alpha decay particle it has relatively low energy and can be stopped by a layer of human skin, so as long as it is not in a gaseous state it is fairly safe and could possibly somehow be used to treat burns; in real life it is being investigated for possible use in radiotherapy for treating certain types of cancer.
The Kazon crew wear the Starfleet combadges on the right side, instead of the familiar left.