I cannot stand Tegan Jovanka. Hate, hate, hate her. The character was a fine example of how Doctor Who was either really good in the ’80’s or truly awful. There was no Laodicean Wholiganism to be had. Tegan was, of course, the lowest of the low.
She was loud, shrill, bossy, and worse yet, the lonest serving companion in terms of consecutive time in the TARDIS--three and one moth.
Yes, I have it calculated down to the month.
Tegan was an Australian flight attendant who never wanted to be a companion. She started traveling in the TARDIS because her aut had been killed by the Master. Shespent her entire three year, one month stint complaining because she wanted to go home and resume her job. Had I been the Fifth Doctor, I would have happily thrown her out the TARDIS. Preferably at a high rate of speed somewhere over Skaro.
The Fifth Doctor did leave her behind once, although accidentally. She became even more of a shrill harpy after she was rescued.
The writers did try to not only end her journey with a redeeming note, but also to use her as a maturing force for the more lighthearted Fifth Doctor. She finally left shortly after another companion, Adric, sacrificed himself to stop a Cybermen plot. Tean decided the Fifth Doctor was a monster himself for letting it happen while showing little emotion. Her departure and rationale for leaving did have an impact. Before regenerating, the Fifth Doctor’s last word was, "Adric!”
I give very little credit to Tean for her eventual impact, but I still despise her in general.