It can be a threat, as it uses Dischord to halve one party member's level, reducing their stats, and it uses the powerful Plasma attack, which may kill a character. Its special attack, Program 17, grants it Shell status, halving the party's magic damage. If fought alone, it will summon three Trappers when defeated; when fought accompanied by Onion Knights, it will summon more of them once they are defeated. For this reason it should be killed first. Casting Thundara works well against it.
The Chaser can teach Strago the DischordLore if encountered on the Veldt. It is advised the player avoid Leaping with Gau, though; if he returns at the end of a battle with a Chaser, the battle end messages will not play and thus Strago will miss his chance to learn Dischord.