In The Crystal Onix, Tracey attempted to use Venonat to find an Onix made out of crystal. It was shown a glass sculpture of it that Mateo's grandfather made and ask to look for something similar. However it only found a pile of rocks but it was still convinced that it found what Tracey wanted.
Not much is known about Venonat's personality. However, it has been shown to become excited if it thinks it has spotted what Tracey is looking for and responds by jumping up and down.
Venonat helps Tracey as a Pokémon watcher by using its eyes to scan the area and locate the Pokémon that Tracey is looking for. It can also use Sleep Powder to make it less likely for the Pokémon to run away. Tracey tends to use it more for Pokémon watching as opposed to battling, for which he favors Marill and Scyther more.