SCP - 5129 is a perpetually growing cat that never stops growing, as of this SCPs writing it is 5 meters long. SCP - 5129 cannot grow in width or height. When something ventures too deep inside of SCP - 5129, it is lost, communication systems like radios are useless after a drone is sent inside 2 meters deep from an open wound.

SCP - 5129 is to be put inside a normal containment chamber with food and water, that's it really.

DATALOG #1: After 2 months in containment SCP - 5129 has increased by 3 meters, now being a 7 meter cat.