This is the only instance in the series of Zack, Billy and Trini piloting Dragonzord in Battlemode without Jason and Kimberly. Most times this combination was used, all 5 original rangers would pilot the zord and Tyrannosaurus would be piloted remotely (if it remained in the battle).
Footage for the intro of the show for Zach can be found here.
Although the monster is called "Spidertron" and is referred to as a spider, it more accurately resembles a wood tick. Still an arachnid, but is not a spider.