Nihilego

Beast Boost (Whenever a creature that was dealt damage by a creature you control this turn dies, put a +1/+1 counter on this creature)
When you cast Nihilego, gain control of target creature for as long as you control Nihilego. All damage that would be dealt to Nihilego is dealt to that creature instead.
UB-01 Symbiont. Observers have been known to suddenly become violent.