TARDIS zoo
From Tardis Wiki, the free Doctor Who reference
The TARDIS zoo was a room in the Doctor's TARDIS.
History
Most of the animals in the TARDIS zoo were endangered. The Doctor hoped to relocate them to a suitable habitat. They were kept in synthetic habitats that were small cuboid boxes. The Sixth Doctor brought a Kymbra Chimera into the zoo while it was disguised as a Swuffle. It broke free and caused a small amount of damage that resulted in several other creatures escaping. (DWM: Changes)
Ace discovered the TARDIS zoo while exploring the ship. She let out a dodo, but it bit her and fled. She caught it and returned it to the zoo. (ST: Echo)