Tentacles

Tentacles are a specied of sentient tentacle which- in a version of the future- take over the world and enslave all humanity

Appearance
Approximately the size of a human, the tentacles are a species of large squishy beings.

After drinking Toxic Sludge, Purple Tentacle grows arms

In Maniac Mansion
Purple tentacle and green tentacle are in the game maniac mansion

In Day of the Tentacle
Lead by Purple Tentacle (after he drinks some Toxic Sludge that gives him arms), the purple tentacles have successfully taken over the world 200 years in the future and enslaved all of humanity as pets