In one account of the genesis of the Daleks, Castavillian placed a plunger which the Fourteenth Doctor retrieved from his TARDIS on the first Dalek to replace the multi-dextrous claw that the TARDIS' accidental arrival had broken off. Upon discovering the modification, Davros decided that he liked it, (TV: Destination: Skaro [+]Russell T Davies, Doctor Who (BBC One, 2023).) leading to what would become known as the suction cup. (PROSE: Dalek Combat Training Manual)
After the Master's body was augmented by "superior" Dalek technology, he had a plunger in place of a right hand, though Emma pointed out that the Master didn't know what it could do. (TV: The Curse of Fatal Death)
Upon seeing a Dalek at a UNIT warehouse, Cleo Proctor observed that it had a toilet plunger sticking out of it. (AUDIO: Recruits)
The Fifteenth Doctor reacted with alarm upon being handed a plunger by Anita Benn, asking if it was armed. (TV: Joy to the World [+]Steven Moffat, Doctor Who Christmas Special 2024 (BBC One and Disney+, 2024).)