Vectus

Vectus are dark blue Cactus monsters with colorful leaves atop their head, resembling typical background plants. However, due to the vectus giving off a constant purple gas akin to that of an Erchius ghost, the camouflage doesn't work as well as it could. Incredibly quick and surprisingly agile, once the Vectus senses prey within striking range, it swiftly springs to the attack.

Vectus are very fast, and capable of teleportation. They rush towards the player and do quite a bit of damage, so it is best to avoid them where possible. The Vectus is also capable of launching blasts of corruption, that inflict the Darkwater Poison debuff on a successful hit. This corrupt poison is the most deadly aspect of this creature, and it uses it frequently.

Vectus can be found on Desert Moon, Desert planets, Irradiated planets, and often found alongside glowing sand.

Luna's Lab Notes
~ The Vectus uses the same spritesheet as the more common Trictus. However, it appears blue in game as it's files contain the following: {"colorSwap":{"1b4c2a":"321b4c","48832f":"2f3a83","629a4b":"4b559a","9bba3d":"3d86ba","d1e160":"60bbe1"}. This coding makes the creature appear as a pale blue, with other minor changes in coloring.

~ The Vectus seems to stop attacking after 3-6 claw swipe attacks, at which point it faces away from the creature it was attacking and remains motionless for several moments before beginning the pursuit anew. It is unknown why this creature waits like this, though it is rumored that the Vectus is actually quite sadistic, and enjoys poisoning it's foes to near death, then pulling back from a head on attack only to watch them wither away and succumb to the poison.

Source:

https://github.com/sayterdarkwynd/FrackinUniverse/tree/master/monsters/walkers/trictusish/trictus2