Penguins (Once Upon a Time-Lord)
Talk about it here.
A group of small penguins could be seen in several locations visited by the Sixth Doctor. The tallest penguin often pointed at the Doctor, and one of the smaller ones wore underwear. (COMIC: Once Upon a Time-Lord, et al.) Sometimes they were a group of four (COMIC: Once Upon a Time-Lord, Party Animals) and sometimes they were a group of three. (COMIC: Kane's Story, The Gift, Time & Time Again)
Encounters with the Doctor
The penguins then saw the Sixth Doctor and Frobisher when they crashed the TARDIS after their encounter with the Funhouse. The tallest penguin pointed at the TARDIS crew for a while and they watched as the TARDIS dematerialised. (COMIC: Kane's Story)
The penguins saw the Sixth Doctor and Peri lounging on a beach on Halcya. The largest penguin was wore swim trunks and held a small bucket and shovel, the medium sized penguin wore a bikini, and the smallest wore swim trunks and a snorkel. (COMIC: The Gift)
When the Sixth Doctor landed his TARDIS in Maruthea, the tallest penguin attempted to get inside it. The penguin told the Doctor that "a friend of his" was inside the TARDIS. The Doctor responded by kicking him out of the TARDIS and dematerialising. The Seventh Doctor and Ace then materialised nearby and walked past the penguins as they comforted the tallest penguin. (COMIC: Party Animals)