Tentacool was caught in Dewford Town at Level 10. Teddy weakened her down with a Scratch, before Emile captured her in a Premier Ball. Emile then gave her the nickname Acooltent, intending for her to be his fourth team member.
Acoolslave's first onscreen use was against a wild Magikarp. She took it out with five Poison Stings, after the first one immediately poisoned Magikarp, helping her steadily deplete its health.
Emile gave Acoolslave the Quick Claw when going to train her up. However, she mainly was switch trained to gain experience. This included against Fisherman Ned, the offscreen battle with Fisherman Elliot, and a few wild Pokémon in Granite Cave. She grew to Level 11 from a wild Aron that Moegami defeated.
After realizing that she has Liquid Ooze for her Ability instead of Clear Body, Emile deposited her in PC after catching a male Tentacool that did have Clear Body. As Emile would use the male Tentacool on his team as Acooltent instead, he gave a speech for the female Tentacool:
"More neglected than Steve. More forgotten than the second A in my username. She was Acooltent. Left to rot in my PC for all eternity, and treated as though she never existed."
Tentacool was finally taken out of the PC, when Chugga needed her for diving underwater.
Chugga wanted to keep her name a secret, but it was shown on the TV.
- Acoolslave shares similarities with the three Feebas which weren't used in Platinum.
- Acoolslave was the second Tentacool used as a HM Slave, the first was Slave MK 2, which was used for Waterfall in FireRed.
- Acoolslave can be seen in the Emerald PC Box in Pokémon Platinum - Episode 79: Park It while Emile is accessing in through Pal Park.