Fusion attack

Warrior Ing are capable of performing a fusion attack. When battling an enemy, it may begin to charge energy of varying colors, before vaulting towards the enemy and covering them in its liquid form, dealing damage as long as it remains on the individual. It is possible that this is another way that the Ing can possess creatures and turn them into Darklings. However, Samus Aran, who possesses the Energy Transfer Module during Metroid Prime 2: Echoes, is immune to this. Samus is not able to end the attack early by entering a Safe Zone. If the Ing misses her, it will impact the ground and liquefy, moving aside before it coalesces into its form again.

Guide
"The Warrior Ing in Oasis Access might try to use a fusion attack-a move in which the Ing launches itself at you and covers your suit in ooze. As long as the gunk is on you, you'll take damage."

The heading for this description in the guide is titled "Metroid Fusion", in reference to the game of the same name.